Connecticut Tax Year 2026

Connecticut 1099-INT Filing Requirements, Tax Year 2026

What Connecticut requires from businesses filing 1099-INT (Interest income) for tax year 2026: deadline, accepted format, CF/SF treatment, registration, and penalties, backed by primary-source citations.

Tax Year 2026 Federal filing satisfies this state Last verified April 28, 2026
Rules below assume no Connecticut tax was withheld on these 1099-INT filings. If you withheld Connecticut income tax, separate or different state filing requirements apply; see conditional rules.
Filing method CF/SF satisfies IRS CF/SF submission covers Connecticut.
Deadline - Deadline pending verification. See deadlines
Format accepted Not applicable Federal CF/SF filing covers this state. See format
Late-filing penalty **Late filing:** $50 per CT-1096 return. See penalties

Filing requirements

Federal filing through the IRS Combined Federal/State Filing (CF/SF) Program satisfies Connecticut's 1099-INT reporting requirement for tax year 2026. No separate state submission is required when the IRS forwards the record to Connecticut under CF/SF.

Connecticut DRS does not require Form 1099-INT to be filed with the state. The DRS information-return filing requirements page enumerates only 1099-MISC, 1099-NEC, 1099-R, 1099-K, and W-2G as the federal forms that must be filed with Connecticut. 1099-INT is not on that list and is not addressed in DRS instructions. Federal-only filing is sufficient.

Deadlines and extensions

Filing deadline
-
BoomTax is verifying the filing deadline.
Holiday/weekend rollover. If the deadline falls on a weekend or a federal holiday, the next business day generally applies. Check with Connecticut for the exact observed calendar before filing.

Accepted format

Federal filing through the IRS Combined Federal/State Filing Program satisfies Connecticut's 1099-INT requirement. No separate state submission is required, so there is no state-specific file format to conform to. The IRS transmits 1099-INT records to Connecticut automatically after accepting the CF/SF submission.

Registration

Registration required: Yes

Filers log into myconneCT with a Business Employer Login or as a Third-Party Bulk Filer (TPBF). DRS requires one filing for each Connecticut Tax Registration Number; multiple locations or payroll systems sharing the same CT Tax Registration Number must combine into a single myconneCT submission. DRS does not assign separate submitter control codes for 1099/W-2G electronic filing.

Late-filing penalties

Connecticut penalty overview

Late filing: $50 per CT-1096 return.

Failure to file 1099-MISC/R/NEC/W-2G with DRS: $5 per form, capped at $2,000 per calendar year.

Failure to file 1099-K with DRS: $50 for the first month per missing 1099-K, plus $50 for each additional month (or fraction thereof) the failure continues, up to $250,000 per year.

Failure to file electronically when required (25+ forms) without a granted waiver: treated as a failure to file; the penalties above may be imposed on payers who file in any other medium without first obtaining a waiver via Form CT-8508.

Frequently asked questions

Does Connecticut require filing of 1099-INT for tax year 2026?

Connecticut accepts 1099-INT through the IRS Combined Federal/State Filing Program, so a separate state submission is generally not required when you file federally under CF/SF.

Does Connecticut participate in the CF/SF program?

Partially. Connecticut accepts CF/SF for some 1099 form types but requires direct filing for others.

What is the Connecticut 1099-INT filing deadline for tax year 2026?

BoomTax is still verifying the tax year 2026 deadline. Check with Connecticut directly for the current due date.

What format does Connecticut accept for 1099-INT?

Because CF/SF filing satisfies Connecticut, the IRS's standard electronic submission (FIRE/IRIS) is the operative format; no state-specific upload is required.

Do I need to file 1099-INT with Connecticut if I also filed federally?

Generally no. Federal filing through CF/SF satisfies Connecticut's 1099-INT requirement, so a separate state filing is typically not needed.

What happens if I miss the Connecticut 1099-INT deadline?

**Late filing:** $50 per CT-1096 return. See the full penalty details below for the complete schedule.

How do I register to file with Connecticut?

Filers log into myconneCT with a Business Employer Login or as a Third-Party Bulk Filer (TPBF). See the registration section above for the full requirements.

Source citations

Verified from 1 primary source
“Connecticut requires 1099-MISC filing even when there is NO Connecticut tax withholding if: (1) payments are made to Connecticut residents, OR (2) payments are made to non-residents for services performed wholly or partly in Connecticut. Out-of-state payers (including those in Wisconsin) must file if either condition is met. Connecticut participates in the Combined Federal/State Filing (CF/SF) program, but only Forms 1099-MISC with NO Connecticut withholding can be satisfied through CF/SF. Forms with withholding must be filed directly with CT DRS through myconneCT.”
Apr 23, 2026 https://portal.ct.gov/drs/withholding-taxes/1099s-electronic-filing-req/filing-requirements

Additional notes

Connecticut requires the state copy of federal Forms 1099-MISC, 1099-NEC, 1099-R, 1099-K, W-2G, and the CT-1096 transmittal to be filed with the Department of Revenue Services (DRS) through myconneCT. Connecticut does participate in the IRS Combined Federal/State Filing Program (CF/SF, state code 08), but CF/SF only satisfies Connecticut's requirement for 1099-MISC, 1099-NEC, and 1099-R when there is no Connecticut withholding. Any 1099-MISC/NEC/R with Connecticut withholding, and all 1099-Ks regardless of withholding, must be filed directly with DRS through myconneCT even if CF/SF was used. Filers of 25 or more information returns must file electronically.

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