The Connecticut tax return mailing address depends on which form you’re sending and whether a check is inside the envelope. For the standard resident or nonresident income tax return (Form CT-1040 or CT-1040NR/PY) with a payment enclosed, mail it to the Department of Revenue Services, P.O. Box 2977, Hartford, CT 06104-2977. If you’re not sending a payment, the box number changes by one digit, so read carefully before you seal the envelope.1CT.gov. DRS Forms, Instructions, and Assistance
Form CT-1040 and CT-1040NR/PY
The two addresses below cover both resident returns (CT-1040) and nonresident or part-year resident returns (CT-1040NR/PY).2Connecticut State Department of Revenue Services. Connecticut Nonresident and Part-Year Resident Income Tax Information
- With payment enclosed: Department of Revenue Services, P.O. Box 2977, Hartford, CT 06104-2977
- Refund or zero balance: Department of Revenue Services, P.O. Box 2976, Hartford, CT 06104-2976
Make the check or money order payable to “Commissioner of Revenue Services.” Write the tax year and your Social Security number on the front of the check, and paper-clip it to the front of the return rather than stapling it or slipping it loose inside.
Paying by Mail After E-Filing
If you filed your return electronically and now want to send a paper check, don’t use the box for returns-with-payment. Payments arriving on their own need Form CT-1040V (the electronic filing payment voucher) and go to a separate processing address:1CT.gov. DRS Forms, Instructions, and Assistance
Department of Revenue Services
Processing
P.O. Box 5088
Hartford, CT 06102-5088
Estimated Tax Payments (CT-1040ES)
Quarterly estimated payments made with Form CT-1040ES go to their own P.O. Box:
Department of Revenue Services
P.O. Box 2932
Hartford, CT 06104-2932
If DRS mailed you preprinted coupons, use them so the payment is credited to the right account.3CT.gov. 2026 Estimated Connecticut Income Tax Payment Coupon for Individuals Form CT-1040ES
Amended Return (CT-1040X)
Amended returns don’t share an address with original returns. Send Form CT-1040X to:
Department of Revenue Services
P.O. Box 2935
Hartford, CT 06104-2935
Attach documentation for whatever you’re changing. If the amendment follows a federal audit or an amended federal return, include the IRS results or your federal Form 1040X. If you’re adjusting a credit such as the Property Tax Credit or Earned Income Tax Credit, attach the corrected schedule or the credit will be disallowed. Put your name and Social Security number on every attachment. Form CT-1040X can also be filed through myconneCT, which is faster than paper.4CT.gov. Form CT-1040X Amended Connecticut Income Tax Return for Individuals 2024 Instructions
Extension Request (CT-1040 EXT)
Form CT-1040 EXT, which pushes your filing deadline to October 15, uses the same two P.O. Boxes as the CT-1040:5Department of Revenue Services, State of Connecticut. Form CT-1040 EXT – Application for Extension of Time to File Connecticut Income Tax Return for Individuals
- With payment: P.O. Box 2977, Hartford, CT 06104-2977
- Without payment: P.O. Box 2976, Hartford, CT 06104-2976
An extension gives you more time to file, not more time to pay. Interest still runs on any unpaid balance from the original April deadline. Two shortcuts eliminate the mailing: paying by credit card through the DRS-approved provider counts as the extension request on its own, and if you owe nothing to Connecticut and already have a federal extension, DRS grants the state extension automatically.
FedEx, UPS, and DHL: Use the Street Address
Private carriers can’t deliver to a P.O. Box. If you’re shipping through FedEx, UPS, or DHL, send the return to the DRS street address:6CT.gov. PS 2016(4) Designated Private Delivery Services
Department of Revenue Services
State of Connecticut
450 Columbus Blvd, Suite 1
Hartford, CT 06103-1837
Only certain service tiers count as timely-filed. Qualifying FedEx services include Priority Overnight, Standard Overnight, 2 Day, and the international tiers. Qualifying UPS services include Next Day Air, Next Day Air Saver, 2nd Day Air, 2nd Day Air A.M., and the Worldwide Express options. DHL Same Day Service also qualifies.7CT.gov. PS 2012(2) Designated Private Delivery Services and Designated Types of Service Ground shipping isn’t on the list. If a deadline is close, choose one of the approved tiers.
Postmark Rule and Proof of Mailing
A mailed return counts as filed on time if the USPS postmark is on or before the due date. What matters is when you handed it to the postal service with proper postage, not when DRS opens it. If the envelope carries both a USPS postmark and a private metered stamp, DRS goes by the USPS postmark, so having the envelope hand-stamped at the post office counter is safer than running it through a private meter when you’re mailing close to the deadline.
USPS Certified Mail or Registered Mail gives you a dated receipt that proves when the return went out. That receipt is worth the small extra cost if DRS ever questions the filing date.
Quick Reference
- Return with payment (CT-1040, CT-1040NR/PY, CT-1040 EXT): P.O. Box 2977, Hartford, CT 06104-2977
- Return without payment (refund or zero balance): P.O. Box 2976, Hartford, CT 06104-2976
- Payment only, sent after e-filing (with Form CT-1040V): P.O. Box 5088, Hartford, CT 06102-5088
- Estimated tax payments (CT-1040ES): P.O. Box 2932, Hartford, CT 06104-2932
- Amended return (CT-1040X): P.O. Box 2935, Hartford, CT 06104-2935
- FedEx, UPS, or DHL delivery: 450 Columbus Blvd, Suite 1, Hartford, CT 06103-1837