Worksheet CT-2210 PE: Underpayment of Estimated Income Tax by Pass-Through Entities (2025)
Connecticut · Connecticut DRS · Used for tax years 2025
Worksheet CT-2210PE calculates interest on underpaid estimated Connecticut Pass-Through Entity Tax for 2025. It includes schedules for annualized income installments and interest calculations. Keep the worksheet for your records and submit it to the Department of Revenue Services
Who files this form
Worksheet CT-2210PE is for filers of Form CT-PET, Connecticut Pass-Through Entity Tax Return, who underpaid their estimated Connecticut Pass-Through Entity Tax.
Do not file this worksheet. Keep it for your records and submit it to the Department of Revenue Services (DRS) only if requested.
Complete it only if:
- Your income varied during the year and the annualized income installment method reduces or eliminates your interest; or
- You want to calculate and pay the interest you owe with your return.
In general, interest applies if your required annual payment is $1,000 or more and you did not make timely installments. If Part 1, Line 4 is less than $1,000, stop and do not complete the worksheet.
When it's due
For tax year 2025 calendar-year filers, the printed estimated payment dates are:
- April 15, 2025
- June 15, 2025
- September 15, 2025
- January 15, 2026
Four equal installments are required. If a payment due date falls on a Saturday, Sunday, or legal holiday, payment is considered timely if filed on the next business day. Fiscal-year filers must adjust the dates to their fiscal year.
For tax year 2025, the worksheet lists March 15, 2026 as the return due date for calendar-year filers. Underpayment interest accrues until that date or the date the underpayment is paid, whichever is earlier.
The worksheet itself is not filed unless DRS requests it.
What you'll need
Have these records and details available to complete the worksheet:
- Your 2025 Form CT-PET and PE Tax amount.
- Your 2024 Form CT-PET and PE Tax amount, if using the prior-year amount to determine your required annual payment.
- Records of estimated tax payments, including amounts and payment dates.
- Any prior-year tax overpayment applied to 2025, along with the prior-year return filing date and any timely extension request.
- Your JobsCT Rebate Credit amount, if claimed.
- The entity's name, address, Federal Employer Identification Number, and Connecticut Tax Registration Number.
If using Schedule A, you also need income subject to PE Tax for each period shown on that schedule.
How to file
Do not submit Worksheet CT-2210PE with your return. Retain a copy and send it to DRS only upon request.
To use the worksheet:
- Complete Part 1 to determine your required annual payment. Stop if Line 4 is less than $1,000.
- Complete Part 2 to calculate underpayments. Use Schedule B to calculate interest for each period showing an underpayment.
- Enter the total interest from Part 2, Line 6 on Form CT-PET, Part 1, Schedule A, Line 9c.
- If using the annualized income installment method, complete Worksheet Schedule A and check the box on Form CT-PET, Part 1, Schedule A, Line 9d.
If you do not complete the worksheet and enter the calculated interest on your return, DRS will calculate any underpayment interest and send you a bill.
Common mistakes
- Filing the worksheet with your return. Keep it in your records unless DRS requests it.
- Continuing when Part 1, Line 4 is below $1,000. The worksheet says to stop at that point.
- Assuming a refund means no interest is due. You may owe underpayment interest even if your return shows a refund.
- Assuming later payments erase earlier interest. Interest is calculated separately for each installment, so an earlier underpayment can still result in interest.
- Missing the annualized-method checkbox. If you use that method, complete Worksheet Schedule A and check Form CT-PET, Part 1, Schedule A, Line 9d.
- Using calendar-year dates for a fiscal year. Fiscal-year filers must adjust the schedule and table dates to reflect their fiscal year.
Questions people ask
How is my required annual payment determined?
Generally, it is the smaller of 90% of the current-year PE Tax or 100% of the prior-year PE Tax. The prior-year option applies only if that taxable year covered 12 months and the entity filed a return for that year.
What interest rate applies to an underpayment?
Interest is 1% per month or fraction of a month. A month runs from the sixteenth day of one month through the fifteenth day of the next. Any fraction of a month counts as a whole month.
Can uneven income during the year reduce my required installments?
Possibly. If you earned more later in the year than earlier, the annualized income installment method may reduce or eliminate one or more required installments. Use Worksheet Schedule A for this calculation.
How do I enter timely estimated payments in Part 2?
Enter cumulative timely payments in each column, including previous installment payments and prior-year overpayments applied to the current year. The instructions give an example of four timely $100 payments: enter $100 in Column A, $200 in Column B, $300 in Column C, and $400 in Column D.