CT-1120 ES: Estimated Corporation Business Tax Payment Coupons (2024)
Connecticut · Connecticut DRS · Used for tax years 2024
Form CT-1120 ES provides payment coupons for the four installments of 2024 estimated Connecticut Corporation Business Tax. The coupons report the corporation or designated taxable member’s identifying information and payment amount due, with schedules to calculate each installmen
Who files this form
Every corporation or combined group carrying on business, or having the right to carry on business, in Connecticut must file if its estimated current-year tax liability on Schedule 1, Line 5, is more than $1,000.
For combined unitary filers, the designated taxable member should make all estimated tax payments using its Connecticut Tax Registration Number.
When it's due
For tax year 2024, the installment deadlines are:
- First installment, CT-1120 ESA: 15th day of the 3rd month of the income year.
- Second installment, CT-1120 ESB: 15th day of the 6th month of the income year.
- Third installment, CT-1120 ESC: 15th day of the 9th month of the income year.
- Fourth installment, CT-1120 ESD: 15th day of the 12th month of the income year.
If a due date falls on a Saturday, Sunday, or legal holiday, the return is considered timely if filed by the next business day.
What you'll need
Have these details and records available to complete the coupons and Schedule 1:
- Connecticut Tax Registration Number and Federal Employer ID Number (FEIN).
- Corporation or designated taxable member name, address, income-year ending date, and return type: Separate or Combined Unitary.
- Prior-year return showing tax, including surtax, before tax credits.
- Estimated current-year tax before credits and estimated Corporation Business Tax credits.
- Prior-year overpayment and amounts paid with earlier installments, as applicable.
- Worksheet CT-1120AE if using an annualized income installment.
Attach an explanation if your closing month has changed. Paper filing requires a waiver from DRS.
How to file
Complete Schedule 1 for the applicable installment to calculate the payment amount. Enter the amount from Line 9 on the coupon's payment amount due line.
File and pay electronically using myconneCT at portal.ct.gov/DRS-myconneCT.
Paper filing is allowed only if DRS has granted a waiver. Form DRS-EWVR, Electronic Filing and Payment Waiver Request, is available at portal.ct.gov/DRS.
If you have received the waiver:
- Complete the coupons in blue or black ink only.
- Make your check payable to Commissioner of Revenue Services.
- Write “2024 Form CT-1120” and the corporation's Connecticut Tax Registration Number on the front of the check.
- Do not use staples.
Mail the coupon and payment to:
Department of Revenue Services
State of Connecticut
PO Box 2974
Hartford, CT 06104-2974
Common mistakes
- Mailing without a waiver: The return must be filed and paid electronically unless DRS has granted a waiver.
- Using the wrong year's form: Each form is year specific. Submit the correct year's form to avoid processing delays.
- Leaving identifying details off a check: For a waived paper payment, write “2024 Form CT-1120” and the corporation's Connecticut Tax Registration Number on the front so payment is applied to the correct account.
- Using staples or the wrong ink: Do not use staples. Paper coupons must be completed in blue or black ink only.
- Not explaining a changed closing month: Attach an explanation if the closing month has changed.
Questions people ask
Can I mail a paper payment coupon?
Only if DRS has granted you a waiver from the electronic filing and payment requirement. Otherwise, file and pay through myconneCT.
Who makes estimated payments for a combined unitary group?
The designated taxable member should make all estimated tax payments using its Connecticut Tax Registration Number. For Schedule 1, Line 1, the prior-year tax is the total tax due from all taxable members that filed with that designated taxable member in the prior year.
How do I account for a prior-year overpayment?
Enter the prior-year overpayment on Schedule 1, Line 8. For the second, third, and fourth installments, Line 8 also includes payments made with the earlier coupons. Subtract Line 8 from Line 7 to calculate Line 9.
Can I use an annualized income installment?
If the corporation establishes that its annualized income installment is less than Schedule 1, Line 9, it must enter the amount from Worksheet CT-1120AE, Line 20, on Line 9. Use Column A for the first installment, B for the second, C for the third, and D for the fourth.