Connecticut Underpayment of Estimated Income Tax by Individuals, Trusts and Estates

Underpayment of Estimated Income Tax by Individuals, Trusts and Estates
Form CT-2210
Department of Revenue Services
State of Connecticut
(Rev. 12/23)
Underpayment

Form CT-2210

of Estimated Income Tax by Individuals, Trusts, and Estates

Your first name and middle initial	

Last name (as shown on your income tax return)	

If a joint return, spouse’s first name and middle initial	

Last name	

Name of estate or trust	

Fiduciary’s name	

Electronic filers: If you are filing electronically, select the indicator for
Form CT‑ 2210 on your Connecticut income tax return. Complete Form
CT-2210 and upload as an attachment.
Paper filers: Check the box for Form CT‑2210 on the front of your
Connecticut income tax return. Place this form at the back of your
completed Connecticut income return.
Purpose: Filers of Forms CT‑1040, Connecticut Resident Income
Tax Return, CT‑1040NR/PY, Connecticut Nonresident and Part‑Year
Resident Income Tax Return, and CT‑1041, Connecticut Income
Tax Return for Trusts and Estates, who underpaid their estimated
Connecticut income tax may use this form to calculate the amount of
interest due or to lower or eliminate interest that would otherwise apply.
My Taxes Are Underpaid: In general, if you do not make timely
installments of your required annual payment and the balance of your
Connecticut income tax is $1,000 or more, you will be charged interest on
the underpaid amount. In determining if the balance of your Connecticut
income tax is $1,000 or more, any Connecticut income tax withheld and
any Pass-Through Entity Tax Credits (PE Tax Credits) you are eligible
to claim must first be applied against the total Connecticut income tax
due. If the result is less than $1,000, you are not subject to interest on
the underpayment.
Your required annual payment is the lesser of:
•	 90% of the income tax shown on your 2023 Connecticut income tax
return; or
•	 100% of the income tax shown on your 2022 Connecticut income tax
return if you filed a 2022 Connecticut income tax return that covered
a 12‑month period.
If either of the following applies to you, you are not subject to interest
on the underpayment. You must check Box F or G in Part 1 below and
attach this page to your Connecticut income tax return:
•	 You were a Connecticut resident during the 2022 taxable year and
did not file a 2022 Connecticut income tax return because you had
no Connecticut income tax liability; or
•	 You were a part‑year resident or nonresident with Connecticut‑sourced
income during the 2022 taxable year but did not file a 2022 Connecticut
income tax return because you had no Connecticut income tax liability.
If you were a Connecticut part‑year resident or nonresident in 2022
and you did not have Connecticut‑sourced income during the 2022
taxable year, you must use 90% of the income tax shown on your 2023
Connecticut income tax return as your required annual payment.
Interest: You may be charged interest if you did not pay enough tax
through withholding, estimated tax payments, or both, by the installment
due dates or if any PE Tax Credit reported to you on Schedule CT K‑1,
Member’s Share of Certain Connecticut Items, Part 3, Line 1; or
Schedule CT‑1041 K‑1, Beneficiary’s Share of Certain Connecticut
Items, Part 4, Line 1, is not sufficient to cover your tax liability. This is
true even if you are due a refund when you file your tax return. Interest
is calculated separately for each installment. Therefore, you may owe
interest for an earlier installment even if you paid enough tax later to

2023

Your Social Security Number

__ __ __ ••• __ __ ••• __ __ __ __
Spouse’s Social Security Number

__ __ __ ••• __ __ ••• __ __ __ __
Federal Employer Identification Number
••
•

__ __

__ __ __ __ __ __ __

make up the underpayment. Overpayment of any estimated tax will be
credited against any future installment.
Interest on the underpayment of estimated income tax, at 1% per month
or fraction of a month, will continue to accrue until the earlier of April 15,
2024, or the date on which the underpayment is paid.
A taxpayer who files his or her income tax return for the taxable year
on or before January 31, 2024, and pays the total amount computed
on the return as payable for the taxable year, does not have to pay
the January  15, 2024, estimate and will not incur interest on the
underpayment of estimated income tax for the fourth required installment.
Do not complete Schedule B, Worksheet D, if you file your income tax
return and pay the tax amount in full by January 31.
Farmers or fishermen who file Forms CT‑1040, CT‑1040NR/PY, or
CT‑1041 for the taxable year on or before March 1, 2024, and pay the
total amount computed on the return as payable for the taxable year,
do not have to pay the January  15, 2024, estimate, which is the only
estimate required, and will not incur interest on the underpayment of
estimated income tax. See Special Rules for Farmers and Fishermen at
portal.ct.gov/DRS/Individuals/Individual-Income-Tax.

Name and Identifying Number

Individuals: Enter in the space provided at the top of the form your name
and Social Security Number (SSN) as it appears on your Connecticut
income tax return. If you filed a joint return, also enter your spouse’s
name and SSN.
Trusts and Estates: Enter the name of the trust or estate and the name
of the fiduciary as it appears on Form CT‑1041 in the space provided
at the top of the form. Also enter the Federal Employer Identification
Number of the trust or estate.
Generally, the rules above also apply in determining whether a
Connecticut resident trust or estate, a nonresident trust or estate, or a
part‑year resident trust has made the required annual payment.
Except as provided below, a trust created in 2023 must use 90% of the
income tax shown on the 2023 Form CT‑1041, as the required annual
payment.

Exceptions

Decedent’s Estates: For any taxable year ending before the date
that is two years after a decedent’s death, the decedent’s estate is not
required to make estimated payments and no underpayment interest
will be charged.
Certain Grantor Trusts: For any taxable year ending before the date
that is two years after a decedent’s death, a trust is not required to make
estimated payments and no underpayment interest will be charged if:
•	 The trust was created under IRC §§ 671 through 679, inclusive, as
owned by the decedent and will receive the residue of the decedent’s
estate under the will; or
•	 If no will is admitted to probate, the trust is primarily responsible for
paying debts, taxes, and expenses of administration.

Part 1 – Reasons For Filing

If one of the following boxes applies to you, you may be able to reduce or eliminate interest charges that would otherwise accrue if we calculated
the interest for you. You must check the box that applies and file this form with your tax return. If you check any of these boxes, also be sure to
check the box for Form CT‑2210 on the front page of your Connecticut income tax return and attach this form to the back of the return.

	A.	 Your income varied during the year and your interest is reduced or eliminated when computed using the annualized income installment method.
	B.	 Your required annual payment is based on the tax shown on your 2022 Connecticut income tax return and you filed or are filing a joint
return for either 2022 or 2023, but not for both years.

	C.	 Your interest is lower by treating your Connecticut income tax withheld from your income as paid on the dates it was actually withheld instead
		

of in equal amounts on the payment due dates.

		

you did not have a Connecticut income tax liability. If you check this box, stop here. Attach this page to your income tax return.

		
		

but you did not file a 2022 Connecticut income tax return because you did not have a Connecticut income tax liability. If you check this 	
box, stop here. Attach this page to your income tax return.

	D.	 You are a farmer or fisherman as defined in IRC § 6654(i)(2). See instructions on Page 7.
	E.	 You cannot use the prior year tax liability as a basis for your required annual payment. See instructions on Page 7.
	F.	 You were a Connecticut resident during the entire 2022 taxable year and you did not file a 2022 Connecticut income tax return because
	G.	 You were a part-year resident or nonresident of Connecticut during the 2022 taxable year and you had Connecticut-sourced income in 2022,
Visit us at portal.ct.gov/DRS for more information.

Page 1 of 10

Part 2 – Required Annual Payment
Complete Part 2 to determine if you were required to make estimated payments. See instructions.
	 1.	 2023 Connecticut income tax ............................................................................................................. 1. 	 ____________________________________
	 2.	 Multiply Line 1 by 90% (.90). Farmers and fishermen, see instructions. ............................................ 2. 	 ____________________________________
	 3.	 Connecticut income tax withheld ........................................................................................................ 3. 	 ____________________________________
	 3a.	 Connecticut Pass‑Through Entity Tax Credit (PE Tax Credit). ......................................................... 3a. 	 ____________________________________
	 4.	 Subtract Line 3 and Line 3a from Line 1. If the result is less than $1,000, stop here. Do not
		 complete or file this form. ................................................................................................................... 4. 	 ____________________________________
	 5.	 Enter your 2022 Connecticut income tax. Part‑year residents, nonresidents, or
individuals with a filing status change from 2022 to 2023 see Part 2: Required Annual
Payment, Line 5, on Page 8. .............................................................................................................. 5. 	 ____________________________________
	 6.	 Enter the smaller of Line 2 or Line 5. This is your required annual payment for 2023. ................ 6. 	 ____________________________________
	 7.	 Subtract Line 3 and Line 3a from Line 6. If the result is zero or less, stop here. Do not
		 complete or file this form. ................................................................................................................... 7. 	 ____________________________________

	

Part 3 – Calculate Your Underpayment and Interest for Each Calendar Quarter See instructions.

A

B

C

D

.25

.50

.75

1.00

.25

.50

.75

1.00

.25

.50

.75

1.00

Total

8. Enter the required annual payment from Part 2, Line 6. Enter the
same amount in Columns A, B, C, and D. If you checked Part 1,
Box A, or Box D, see instructions.
9. Installment percentages
10. Multiply Line 8 by Line 9. Enter each result in the appropriate
column. If you checked Part 1, Box A, see instructions.
11. Enter the total Connecticut tax withheld, Part 2, Line 3. Enter the
same amount in Columns A, B, C, and D. If you checked Part 1,
Box C, skip this line and see instructions for Line 11b.
11a. Withholding percentages
11b. Multiply Line 11 by Line 11a and enter each result in the appropriate
column, or if you want Connecticut income tax withholding to
apply when it was actually withheld, enter the actual cumulative
withholding amounts for each period in the appropriate box.
12. Enter the total Connecticut Pass‑Through Entity Tax Credit, from Part 2,
Line 3a, above. Enter the same amount in Columns A, B, C, and D.
12a. PE Tax Credit percentages
12b. Multiply Line 12 by Line 12a. Enter each result in the
appropriate column.
13. Add Line 11b and Line 12b. Enter each result in the
appropriate column.
14. Subtract Line 13 from Line 10. Enter each result in the appropriate
column. If Line 13 is equal to or greater than Line 10 in any
column, enter “0” in that column.
15. Enter the estimated tax payments. See instructions.
16. Underpayments - Subtract Line 15 from Line 14. Enter each result
in the appropriate column. If Line 15 is equal to or greater than
Line 14 in any column, enter “0” in that column.
17. Interest - Use Worksheets A, B, C, and D of Schedule B and enter
each result in the appropriate column. Add Columns A, B, C, and D.
Enter the total in the Total Column and on the appropriate line of
your Connecticut income tax return.

Attach this form to the back of your Connecticut income tax return. Keep a copy of this worksheet for your records.
Form CT-2210 Back (Rev. 12/23)

Visit us at portal.ct.gov/DRS for more information.

Page 2 of 10

Schedule A

Annualized Income Installment Schedule

See Schedule A - Annualized Income Installment, General Instructions on Page 9.

If you complete this schedule, attach it to Form CT‑2210. Keep a copy of this schedule for your records.

	
(a)	(b)	(c)	(d)
	

	
1-1-2023	1-1-2023	1-1-2023	1-1-2023
	
to	to	to	to
	
3-31-2023	
5-31-2023	
8-31-2023	
12-31-2023

Trusts and estates should not use the period ending
dates shown to the right. Instead, use 2-28-2023,
4-30-2023, 7-31-2023, and 11-30-2023.

1.	 Enter your Connecticut adjusted gross income for each
period. See instructions.	

1.

2.	 Annualization amounts: Trusts and estates, see
instructions on Page 9.	

2.

3.	 Annualized income: Multiply Line 1 by Line 2.	

3.

	
4	2.4	1.5	1

4.	 Enter the tax for the amount on Line 3. Nonresidents,
part-year residents, and nonresident trusts, see instructions. 	 4.
5.	 Credit for income taxes paid to qualifying jurisdictions:
Residents and part‑year residents only, see instructions.	

5.

6.	 Subtract Line 5 from Line 4.	

6.

7.	 Connecticut alternative minimum tax: See instructions.	

7.

8.	 Add Line 6 and Line 7.	

8.

9.	 Credit for property taxes paid on your primary residence
or motor vehicle, or both: Residents only, see instructions.	 9.
10.	Subtract Line 9 from Line 8. If less than zero, enter “0.”	

10.

11.	Allowable credits from Schedule CT‑IT Credit, Part 1,
Line 11: See instructions.	

11.

12.	Subtract Line 11 from Line 10.	

12.

13.	Applicable percentages	

13.

14.	Multiply Line 12 by Line 13.	

14.

	
0.225	0.45	0.675	0.90

Complete Lines 15 - 25 in one column before going to the next column.
15.	Add the amounts in all preceding columns of Line 21.	

15.

16.	Annualized income installment: Subtract Line 15 from
Line 14. If zero or less, enter “0.”	

16.

17.	Enter 25% (.25) of your required annual payment from
Form CT‑2210, Part 2, Line 6, in each column.	

17.

18.	Enter amount from Line 20 of the preceding column of
this schedule.	

18.

19.	Add Line 17 and Line 18 and enter the total.	

19.

20.	Subtract Line 16 from Line 19.
If less than zero, enter “0.”	

20.

21.	Enter the smaller of Line 16 or Line 19.	

21.

22.	Enter the amount from Line 21, Column (a) here and on
Form CT‑2210, Part 3, Line 10, Column A. 	

22.

23.	Add Line 21, Column (b) and Line 22, Column (a). Enter
here and on Form CT‑2210, Part 3, Line 10, Column B.	

23.

24.	Add Line 21, Column (c) and Line 23, Column (b). Enter
here and on Form CT‑2210, Part 3, Line 10, Column C.	

24.

25.	Add Line 21, Column (d) and Line 24, Column (c). Enter
here and on Form CT‑2210, Part 3, Line 10, Column D.	

25.

Form CT-2210 Schedule A (Rev. 12/23)

Visit us at portal.ct.gov/DRS for more information.

Page 3 of 10

Schedule B

Interest Calculation

See Schedule B - Interest Calculation, General Instructions on Page 9.

Worksheet A — For period beginning after April 15, 2023, and ending on or before June 15, 2023.
			Interest
	
Date	
Amount	
Rate	
1	

	

2	

Line a	 -	Underpayment			
Line b	-	Late payment	

3	4
.01

4-16-2023 to 5-15-2023

Line c	 -	Revised underpayment			
Line d	-	Late payment	

Interest

.01

5-16-2023 to 6-15-2023

Line e	-	Total interest

Worksheet B — For period beginning after June 15, 2023, and ending on or before September 15, 2023.
1	

	

2	

Line a	 -	Underpayment			
Line b	-	Late payment	

.01

7-16-2023 to 8-15-2023

Line e	-	Revised underpayment			
Line f	 -	Late payment	

.01

6-16-2023 to 7-15-2023

Line c	 -	Revised underpayment			
Line d	-	Late payment	

3	4

.01

8-16-2023 to 9-15-2023

Line g	-	Total interest

Worksheet C — For period beginning after September 15, 2023, and ending on or before January 15, 2024.
1	

	

2	

Line a	 -	Underpayment			
Line b	-	Late payment	

.01

11-16-2023 to 12-15-2023

Line g	-	Revised underpayment			
Line h	-	Late payment	

.01

10-16-2023 to 11-15-2023

Line e	-	Revised underpayment			
Line f	 -	Late payment	

.01

9-16-2023 to 10-15-2023

Line c	 -	Revised underpayment			
Line d	-	Late payment	

3	4

.01

12-16-2023 to 1-15-2024

Line i	 -	Total interest

Worksheet D — For period beginning after January 15, 2024, and ending on or before April 15, 2024.
1	

	

2	

Line a	 -	Underpayment			
Line b	-	Late payment	

.01

2-16-2024 to 3-15-2024

Line e	-	Revised underpayment			
Line f	 -	Late payment	

.01

1-16-2024 to 2-15-2024

Line c	 -	Revised underpayment			
Line d	-	Late payment	

3	4

.01

3-16-2024 to 4-15-2024

Line g	-	Total interest

Form CT-2210 Schedule B (Rev. 12/23)

Keep a copy of this schedule for your records.
Visit us at portal.ct.gov/DRS for more information.

Page 4 of 10

Worksheet 1
Nonresidents and Part-Year Resident Individuals
See Schedule A - Annualized Income Installment on Page 9.
Nonresidents and part-year resident individuals must use the schedules and worksheets from Form CT‑1040NR/PY to
determine Connecticut-sourced income. Nonresident trusts and estates and part-year resident trusts must use the schedules
and worksheets from Form CT-1041 to determine Connecticut-sourced income.
To calculate the tax, complete the worksheet below for each column. If you complete this worksheet, attach it to Form CT-2210.
First Installment - January 1, 2023 to March 31, 2023
	 a.	 Annualized income from Schedule A, Line 3, Column (a) ....................................................
	 b.	 Annualized Connecticut-sourced income .............................................................................
	 c.	 Enter the greater of Line a or Line b. ...................................................................................
	 d.	 Enter the tax due on Line c using the tax tables or the Tax Calculation Schedule.
Trusts and estates: Multiply Line c by 6.99% (.0699). .......................................................
	 e.	 Divide Connecticut-sourced income for the period by Connecticut adjusted gross income
(Connecticut taxable income for trusts and estates) for the period. This is your allocated
Connecticut income tax percentage. If Line b is greater than Line a, enter 1.0000. ................

•

	 f.	 Multiply Line d by Line e. Enter here and on Schedule A, Line 4, Column (a). .........................

First and Second Installments - January 1, 2023 to May 31, 2023
	 a.	 Annualized income from Schedule A, Line 3, Column (b) ....................................................
	 b.	 Annualized Connecticut-sourced income .............................................................................
	 c.	 Enter the greater of Line a or Line b. ...................................................................................
	 d.	 Enter the tax due on Line c using the tax tables or the Tax Calculation Schedule.
Trusts and estates: Multiply Line c by 6.99% (.0699). .......................................................
	 e.	 Divide Connecticut-sourced income for the period by Connecticut adjusted gross income
(Connecticut taxable income for trusts and estates) for the period. This is your allocated
Connecticut income tax percentage. If Line b is greater than Line a, enter 1.0000. ................

•

	 f.	 Multiply Line d by Line e. Enter here and on Schedule A, Line 4, Column (b). ....................
Complete the Third and Fourth Installments on Page 6.

Form CT-2210 Worksheet 1 (Rev. 12/23)

Visit us at portal.ct.gov/DRS for more information.

Page 5 of 10

Third Installment - January 1, 2023 to August 31, 2023
	 a.	 Annualized income from Schedule A, Line 3, Column (c) ....................................................
	 b.	 Annualized Connecticut-sourced income .............................................................................
	 c.	 Enter the greater of Line a or Line b. ...................................................................................
	 d.	 Enter the tax due on Line c using the tax tables or the Tax Calculation Schedule.
Trusts and estates: Multiply Line c by 6.99% (.0699). .......................................................
	 e.	 Divide Connecticut-sourced income for the period by Connecticut adjusted gross income
(Connecticut taxable income for trusts and estates) for the period. This is your allocated
Connecticut income tax percentage. If Line b is greater than Line a, enter 1.0000. ............

•

	 f.	 Multiply Line d by Line e. Enter here and on Schedule A, Line 4, Column (c)......................

Fourth Installment - January 1, 2023 to December 31, 2023
	 a.	 Annualized income from Schedule A, Line 3, Column (d) ...................................................
	 b.	 Annualized Connecticut-sourced income ............................................................................
	 c.	 Enter the greater of Line a or Line b. ..................................................................................
	 d.	 Enter the tax due on Line c using the tax tables or the Tax Calculation Schedule.
Trusts and estates: Multiply Line c by 6.99% (.0699). ......................................................
	 e.	 Divide Connecticut-sourced income for the period by Connecticut adjusted gross income
(Connecticut taxable income for trusts and estates) for the period. This is your allocated
Connecticut income tax percentage. If Line b is greater than Line a, enter 1.0000. ...........

•

	 f.	 Multiply Line d by Line e. Enter here and on Schedule A, Line 4, Column (d). ...................

Form CT-2210 Worksheet 1 (Rev. 12/23)

Visit us at portal.ct.gov/DRS for more information.

Page 6 of 10

Form CT-2210 Instructions
Do not file this form unless:
•	 You checked one of the boxes in Part 1; or
•	 You wish to calculate and pay the interest you owe with your
return.
If you do not file this form, the Department of Revenue Services
(DRS) will calculate interest on any underpayment of estimated tax
you owe and send you a bill. The interest on the underpayment of
estimated tax will stop accruing on the earlier of the date you pay
your total tax liability or April 15, 2024.
Please note that each form is year specific. To prevent any delay in
processing your return, the correct year’s form must be submitted to DRS.
When Are My Payments Due? In general, four equal installments
of estimated tax are required on April 15, June 15, September 15,
and January 15. Fiscal year filers should follow federal filing dates.
If the due date falls on a Saturday, Sunday, or legal holiday, the
payment will be considered timely if filed on the next business day.
Estates and certain trusts are required to make estimated income
tax payments as stated above for any taxable year ending two or
more years after the date of the decedent’s death. For additional
information on when certain trusts are required to make estimated
income tax payments, see IRC §§ 671 through 679.
Special Rules for Farmers and Fishermen: If you are a farmer
or fisherman, as defined in IRC § 6654(i)(2), your required annual
payment is the lesser of:
•	 662/3% of the income tax shown on your 2023 Connecticut income
tax return; or
•	 .100% of the income tax shown on your 2022 Connecticut income
tax return, if you filed a 2022 income tax return that covered a
12‑month period.
Farmers and fishermen are required to make only one installment
of estimated income tax for the taxable year. If you are a farmer or
fisherman, you must do one of the following:
•	 Pay the required installment on or before January 15, 2024; or
•	 File your 2023 Connecticut income tax return on or before March 1,
2024, and pay the full amount computed on the return. In this
case, do not make an estimated income tax payment for 2023.
See the instructions for Box D.

Part 1: Reasons for Filing
Complete Part 1 only if one of the following boxes applies to you.
By checking the box that applies to you, you may be able to reduce
or eliminate interest charges that would otherwise accrue if we
calculated the interest for you under the normal requirements for
making estimated tax payments. If you check any of the boxes in
Part 1, also check the box for Form CT‑2210 on the front page of
your Form CT‑1040, Form CT‑1041, or Form CT‑1040NR/PY.
You may only use 100% of your 2022 Connecticut income tax to
calculate your required annual payment if:
•	 You filed a 2022 Connecticut income tax return that covered a
12‑month period; or
•	 During the 2022 taxable year, you were a resident, part-year
resident, or nonresident with Connecticut-sourced income and
you did not file a 2022 Connecticut income tax return because you
did not have a Connecticut income tax liability. See Part 2, Line 5,
for instructions on calculating your required annual payment.
Box A: Check this box if you are using the annualized income
installment method. If your income fluctuated during the year, this
method may reduce or eliminate the amount of one or more required
quarterly payments. See Schedule A - Annualized Income Installment,
General Instructions, on Page 9.
Form CT-2210 Instructions (Rev. 12/23)

If you were a part‑year resident who moved into Connecticut in 2023
and you cannot use the prior year tax liability as the basis of the
required annual payment, you may benefit by using the annualized
installment method to report Connecticut‑sourced income in the
period(s) in which it was earned.
Box B: Check this box if your estimated tax payments were based on
the tax shown on your 2022 Connecticut income tax return and your
filing status changed from last year. See instructions for Changes
in Filing Status in Part 2, Line 5.
Box C: Check this box if you want income tax withheld in 2023 to
be applied when it was actually withheld rather than in four equal
installments. See instructions for Part 3, Line 11 and Line 11b.
Box D: Check this box if you are a farmer or fisherman and:
•	 You are required to make only one installment of estimated
Connecticut income tax; or
•	 You have filed your tax return for the taxable year on or before
March 1, 2024, and have paid the amount computed on the return
as payable for the taxable year. Stop here and do not complete
Part 2 and Part 3.
Attach Page 1 of Form CT‑2210 to your Connecticut income tax return
and check the box for Form CT‑2210 on the front of Form CT‑1040
or CT‑1040NR/PY.
Box E: Check this box if you were a part‑year resident or
nonresident of Connecticut during the 2022 taxable year, did not
have Connecticut‑sourced income, and were not required to file a
Connecticut income tax return. If you check Box E, you must use
90% of your 2023 income tax as your required annual payment.
Box F: Check this box if you were a Connecticut resident during
the entire 2022 taxable year and you did not file a 2022 Connecticut
income tax return because you did not have a Connecticut income
tax liability. Stop here and do not complete Part 2 and Part 3. Attach
Page 1 of this form to your income tax return.
Box G: Check this box if you were a part‑year resident or
nonresident of Connecticut during the 2022 taxable year and you
had Connecticut‑sourced income in 2022, but you did not file a
2022 Connecticut income tax return because you did not have a
Connecticut income tax liability. Stop here and do not complete Part 2
and Part 3. Attach Page 1 of this form to your income tax return.
Visit portal.ct.gov/DRS/Individuals/Individual-Income-Tax to obtain
information on the filing requirements and gross income test for
Connecticut residents and for nonresidents and part-year residents
of Connecticut, as well as examples of Connecticut‑sourced income.

Part 2: Required Annual Payment
Line 1: Enter the amount of income tax shown on your 2023
Connecticut income tax return (Form CT‑1040, Line  14; Form
CT‑1040NR/PY, Line  16; or Form CT‑1041, Line  9). Do not
subtract estimated payments, Pass‑Through Entity Tax Credits, or
Connecticut tax withheld in 2023.
Line 2: Farmers and fishermen multiply Line 1 by 662/3%.
Line 3: Enter Connecticut income tax withheld in 2023. This
amount includes income tax withholding reported on Forms W-2
or 1099 and Schedule CT K‑1, Part 4, Line 1 (an amount may be
reported to you on a Schedule CT  K‑1 if you are a nonresident
individual member of a pass‑through entity, and the pass‑through
entity elected to remit a composite income tax payment on behalf
of their nonresident members). Do not enter any estimated tax
payments or taxes withheld for the Internal Revenue Service (IRS)
or other jurisdictions.
Line 3a: Enter any Pass‑Through Entity Tax Credit reported on
Schedule CT­‑PE, Line 1; or Schedule CT‑1041 K‑1, Part 4, Line 1.
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Line 5: If your filing status was the same on your 2022 and 2023
Connecticut income tax returns and your 2022 Connecticut income
tax return covered a 12‑month period, enter 100% of the income tax
shown on your 2022 Connecticut income tax return (Form CT‑1040,
Line 14; Form CT‑1040NR/PY, Line 16; or Form CT‑1041, Line 9).
If you did not file a 2022 Connecticut income tax return because
you did not have a Connecticut income tax liability and you
were a resident, nonresident, or part‑year resident in 2022 with
Connecticut‑sourced income, enter “0.”
If you were a part‑year resident or nonresident in 2022 and you
did not have Connecticut‑sourced income during the 2022 taxable
year, leave Line 5 blank and enter the amount from Line 2 as your
required annual payment on Line 6.
Changes in Filing Status From 2022 to 2023: If you are filing a joint
Connecticut return for 2023 but filed separate Connecticut returns
for 2022 as single, married filing separately, or head of household,
you must combine your 2022 separate tax liabilities to determine
your combined 2022 income tax. If either you or your spouse did
not file a 2022 Connecticut income tax return, see the instructions
for Part 1, Box E, to determine if you can use the prior year tax as
the basis for your required annual payment.
If you are filing Connecticut returns as filing separately for 2023 but
filed a joint Connecticut return for 2022, you must determine your share
of the 2022 tax (Form CT‑1040, Line 14, or Form CT‑1040NR/PY,
Line  16). First calculate the 2022 tax both you and your spouse
would have paid had you filed separate Connecticut returns for 2022
as married persons filing separately. Then complete the following
calculation:
Your separate 2022 tax liability
Both spouses’ separate 2022 tax liabilities

X

Your 2022 joint tax liability

Examples
The following taxpayers, after subtracting Connecticut income tax
withheld, have a 2023 Connecticut income tax liability of more than
$1,000 and may be liable for interest on the underpayment of their
estimated Connecticut income tax.
Anita, a resident of Connecticut during the entire 2022 taxable
year, filed a 2022 resident income tax return.
Anita’s 2023 required annual payment is the lesser of 100%
of the income tax shown on her 2022 Connecticut income tax
return or 90% of the income tax shown on her 2023 Connecticut
income tax return.
If none of the reasons on CT‑2210, Part 1 apply to her, Anita is
liable for interest on the underpayment of estimated Connecticut
income tax. Anita is not required to complete Form CT‑2210.
DRS will calculate the interest and bill her.
Bill, a resident of Connecticut during the entire 2022 taxable
year, did not file a 2022 Connecticut income tax return because
he had no 2022 Connecticut income tax liability. Bill’s 2023
required annual payment is zero.
Bill must check Box F on Form CT‑2210, check the box on
Page 1 of Form CT‑1040 that he completed Form CT‑2210, and
attach Form CT‑2210 to his 2023 Connecticut income tax return.
Jim, a part‑year resident or nonresident of Connecticut during
the 2022 taxable year, had Connecticut‑sourced income in 2022
but did not file a 2022 Connecticut income tax return because
he had no 2022 Connecticut income tax liability. Jim’s 2023
required annual payment is zero.
Jim must check Box G on Form CT‑2210, check the box on
Page  1 of Form CT‑1040 or Form CT‑1040NR/PY that he
completed Form CT‑2210, and attach Form CT‑2210 to his
2023 Connecticut income tax return.
Form CT-2210 Instructions (Rev. 12/23)

Sara, a nonresident or part‑year resident of Connecticut during
the 2022 taxable year, had no Connecticut‑sourced income
in 2022 and did not file a 2022 Connecticut income tax return
because she had no 2022 Connecticut income tax liability.
Sara’s 2023 required annual payment is 90% of the income tax
shown on her 2023 Connecticut income tax return.
Sara must check Box E on Form CT‑2210, check the box on
Page  1 of Form CT‑1040 or Form CT‑1040NR/PY that she
completed Form CT‑2210, and attach Form CT‑2210 to her
2023 Connecticut income tax return.
David, a resident, part‑year resident, or nonresident of
Connecticut during the 2022 taxable year, had a Connecticut
income tax liability in 2022 but in error did not file a 2022
Connecticut income tax return.
When David files his 2023 income tax return his required annual
payment will be the lesser of 90% of the income tax shown on
his 2023 Connecticut income tax return or 100% of the income
tax shown on his 2022 Connecticut income tax return. Because
David did not file a 2022 Connecticut income tax return, his
required annual payment is 90% of the income tax shown on
his 2023 Connecticut income tax return.
Eric, a nonresident of Connecticut during the 2022 taxable year,
had no Connecticut‑sourced income in 2022 and did not file a 2022
Connecticut income tax return because he had no Connecticut
income tax liability. Eric moved to Connecticut in June 2023 and,
as a part‑year resident of Connecticut in 2023, files a 2023 Form
CT‑1040NR/PY.
Eric’s 2023 required annual payment is 90% of the income tax
shown on his 2023 Connecticut income tax return.
Eric must check Box E on Form CT‑2210. Because Eric moved to
Connecticut in June, he may benefit by checking Box A and using
the annualized income installment method to compute the interest.
Kim, a part‑year resident of Connecticut during the 2022 taxable
year, filed a 2022 Form CT‑1040NR/PY that covered a 12‑month
period and files a 2023 Form CT‑1040.
Kim’s 2023 required annual payment is the lesser of 90% of the
income tax shown on her 2023 Connecticut income tax return
or 100% of the income tax shown on her 2022 Connecticut
income tax return.
If none of the reasons on CT‑2210, Part 1 apply to Kim, Kim is
liable for interest on the underpayment of estimated Connecticut
income tax. Kim is not required to complete Form CT‑2210.
DRS will calculate the interest and bill her.
Tim, a resident of Connecticut during the 2022 taxable year,
filed as married filing jointly on his 2022 Form CT‑1040 and as
single on his 2023 Form CT‑1040.
Tim’s 2023 required annual payment is the lesser of 90% of his
2023 Connecticut income tax liability or 100% of his separate
2022 Connecticut income tax liability as computed using the
formula on the left.
If Tim is using 100% of his separate 2022 Connecticut income
tax liability, Tim must check Box B, check the box on Page 1
of Form CT‑1040 that he completed Form CT‑2210, and attach
Form CT‑2210 to his 2023 Connecticut income tax return.

Part 3 - Calculate Your Underpayment and Interest
Line 8: If you are using the annualized income installment method,
skip Line 8 and Line 9 and go on to Line 10. Be sure you also
check Part 1, Box A.
If you checked Part 1, Box D, because you are a farmer or fisherman
and you have made only one installment of estimated income tax,
complete Column D only.
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Line 10: If you checked Part 1, Box A, because you are using the
annualized income installment method, enter the amounts from
Schedule A - Annualized Income Installment Schedule, Lines 22
through 25, in the appropriate columns. Attach Schedule A to Form
CT‑2210 and also include your computations of your Connecticut
adjusted gross income for each period.
Line 11: Enter the total amount of Connecticut income tax withheld
in 2023 in Columns A, B, C, and D. Do not enter estimated tax
payments or taxes withheld for the IRS or other jurisdictions.
Example: If your total 2023 Connecticut income tax withheld
was $1,300, enter $1,300 in Columns A, B, C, and D.
If you want Connecticut income tax withholding to apply when it was
actually withheld, skip Line 11 and Line 11a and go on to Line 11b.
Be sure you also check Part 1, Box C.
Line 11b: Multiply Line 11 by Line 11a, or if you want Connecticut
income tax withholding to apply when it was actually withheld,
enter the actual cumulative withholding amounts on this line in the
appropriate column.
Example: If $600 was withheld in March, $200 in May, $200
in August, and $300 in November, enter $600 in Column A,
enter $800 in Column B, $1,000 in Column C, and $1,300 in
Column D.
Line 12: Enter the total Connecticut Pass‑Through Entity Tax Credit,
from Part 2, Line 3a. Enter the same amount in Columns A, B, C, and D.
Line 15: Enter in the appropriate columns all timely installment
payments you made. Timely installment payments are all payments
(other than any tax withheld) made on or before the estimated
payment due date(s) including any previous installment payments.
Example: If estimated Connecticut income tax payments of
$100 each were made on April  15, June  15, September  15,
2023, and on January 15, 2024, enter $100 in Column A, $200
in Column B, $300 in Column C, and $400 in Column D.

Schedule A - Annualized Income Installment
General Instructions
You may benefit from using the annualized income installment
method if your income varied throughout the year because you
earned more money later in the year than you did in the early part
of the year, such as from lottery winnings, investment income, or
self‑employment income.
By using this method, you may be able to reduce or eliminate the
amount of one or more required installments.

4.	 Attach your calculations of your Connecticut adjusted gross
income for each period; and
5.	 Check the box for Form CT‑2210 on the front of your Connecticut
income tax return.

Line Instructions
Line 1: Attach a schedule showing how you computed your
Connecticut adjusted gross income for each period.
Trusts and estates must enter their Connecticut taxable income
and use the following period ending dates: 2-28-2023, 4-30-2023,
7-31-2023, and 11-30-2023.
Line 2: Trusts and estates do not use the amounts shown in
Columns (a) through (d). Instead, use 6, 3, 1.71429, and 1.09091,
as the annualization amounts.
Line 4: Resident individuals must compute the tax on the amount
shown on Line 3 using the Tax Tables or the Tax Calculation
Schedule.
Resident trusts and estates multiply Line 3 by 6.99% (.0699).
Nonresidents and part-year resident individuals see Worksheet 1
on Page 5.
Nonresident trusts and estates and part-year resident trusts
see Worksheet 1 on Page 5.
Line 5: The credit for tax paid to a qualifying jurisdiction is based
wholly or partly on the annualized income for each period.
Line 7: You must annualize your adjusted federal alternative
minimum taxable income using the annualization amounts on Line 2.
Use Form CT‑6251, Connecticut Alternative Minimum Tax Return
- Individuals, as a guide.
Line 9: Resident Individuals - Enter the credit for property taxes paid
on your primary residence, motor vehicle, or both, as calculated on
your 2023 Form CT‑1040, Schedule 3.
The credit may not exceed $300 and may be further reduced. Refer
to Form CT‑1040, Schedule 3, and instructions when calculating
the credit.
Line 11: The allowable Connecticut income tax credits from
Schedule CT‑IT Credit, Income Tax Credit Summary, Part 1, Line 11,
is based wholly or partly on the annualized income for each period.
Lines 15 through 25: You must complete Lines 15 through 25 in
one column before continuing to the next column.

Schedule B - Interest Calculation
General Instructions
Complete the worksheet for any period where an underpayment is
shown on Form CT‑2210, Part 3, Line 16.

For information on filing estimated tax payments using the annualized
income installment method, see Informational Publication 2018(11),
A Guide to Calculating Your Annualized Estimated Income Tax
Installments and Worksheet CT‑1040 AES. This publication is
available from the DRS website at portal.ct.gov/DRS.

Example: If an underpayment is shown in Part  3, Line  16,
Column B, complete Worksheet B. If no underpayment is shown
in Part 3, Line 16, Column B, but an underpayment is shown
in Part 3, Line 16, Column C, skip Worksheet B and complete
Worksheet C.

If you use the annualized income installment method for any
installment due date, you must use this method for all installment
due dates. Form CT‑2210, Schedule A, automatically selects the
smaller of the annualized income installment or regular installment
increased by the amount saved by using the annualized income
installment method in computing earlier installments.

Interest at 1% per month or fraction of a month will continue to
accrue until the earlier of April 15, 2024, or the date on which the
underpayment is paid. A month is measured from the sixteenth day
of the first month to the fifteenth day of the next month. Any fraction
of a month is considered a whole month.

If you use the annualized income installment method, you are
required to complete all of the following steps:

Worksheet A

1.	 Check Box A on Form CT‑2210, Part 1;
2		Enter the amounts from Schedule A, Lines 22 through 25 in the
appropriate columns on Form CT‑2210, and complete Part 3;
3.	 Attach Form CT‑2210 and Schedule A to your return (nonresident
and part-year resident individual, include Worksheet 1);

Form CT-2210 Instructions (Rev. 12/23)

Line a: Enter in Column 2 the underpayment shown on Form
CT‑2210, Part 3, Line 16. Multiply Column 2 by Column 3 and enter
the result in Column 4.
Line b: Enter in Column 2 the amount paid during the period listed in
Column 1. If multiple payments were made during the period listed,
combine those payments and enter the total.
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Line c: Subtract Line b from Line a in Column 2 and enter the result
in Column 2. Multiply Column 2 by Column 3 and enter the result
in Column 4.
Line d: Follow the instructions for Line b.
Line e: Add all amounts in Column  4. Enter the total on Form
CT‑2210, Part 3, Line 17, Column A.
Worksheet B
Line a: Enter in Column 2 the underpayment shown on Form
CT‑2210, Part 3, Line 16. Multiply Column 2 by Column 3 and enter
the result in Column 4.
Line b: Enter in Column 2 the amount paid during the period listed in
Column 1. If multiple payments were made during the period listed,
combine those payments and enter the total.
Line c: Subtract Line b from Line a in Column 2 and enter the result
in Column 2. Multiply Column 2 by Column 3 and enter the result
in Column 4.
Line d: Follow the instructions for Line b.
Line e: Subtract Line d from Line c in Column 2 and enter the result
in Column 2. Multiply Column 2 by Column 3 and enter the result
in Column 4.
Line f: Follow the instructions for Line b.
Line g: Add all amounts in Column  4. Enter the total on Form
CT‑2210, Part 3, Line 17, Column B.

Form CT-2210 Instructions (Rev. 12/23)

Worksheet C
Lines a through d: Follow the instructions for Lines a through d
on Worksheet B.
Lines e and f: Follow the instructions for Lines e and f on
Worksheet D.
Line g: Subtract Line f from Line e in Column 2 and enter the result
in Column 2. Multiply Column 2 by Column 3 and enter the result
in Column 4.
Line h: Enter in Column 2 the amount paid during the period listed in
Column 1. If multiple payments were made during the period listed,
combine those payments and enter the total.
Line i: Add all amounts in Column  4. Enter the total on Form
CT‑2210, Part 3, Line 17, Column C.
Worksheet D
Lines a through d: Follow the instructions for Lines a through d
on Worksheet B.
Line e: Subtract Line d from Line c in Column 2 and enter the result
in Column 2. Multiply Column 2 by Column 3 and enter the result
in Column 4.
Line f: Enter in Column 2 the amount paid during the period listed in
Column 1. If multiple payments were made during the period listed,
combine those payments and enter the total.
Line g: Add all amounts in Column  4. Enter the total on Form
CT‑2210, Part 3, Line 17, Column D.

Page 10 of 10