Colorado 1099-INT Filing Requirements, Tax Year 2026

Q: Does Colorado require direct filing of 1099-INT for tax year 2026?

Federal filing through the Combined Federal/State Filing Program satisfies Colorado's 1099-INT requirement. Deadline: Federal e-file deadline.

Filing method CF/SF satisfies IRS CF/SF submission covers Colorado.

Deadline Federal e-file deadline See deadlines section for holiday rollover. See deadlines

Format accepted Not applicable Federal CF/SF filing covers this state. See format

Late-filing penalty **Failure-to-file penalty:** $5 to $50 per W-2/1099 not filed timely, at the Department's discretion (C. See penalties

Filing requirements

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

Colorado participates in the IRS Combined Federal/State Filing (CF/SF) Program, so 1099-INT data is forwarded automatically when the filer opts in. A separate Colorado submission is required only when Colorado state income tax was withheld on the interest payment, in which case the 1099-INT must be filed through Revenue Online with Form DR 1106 by January 31.

Deadlines and extensions

Filing deadline

Federal e-file deadline

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

Accepted format

Federal filing through the IRS Combined Federal/State Filing Program satisfies Colorado'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 Colorado automatically after accepting the CF/SF submission.

Registration

Registration required: Yes

Anyone submitting W-2s, 1099s, or W-2Gs must register as a Withholding Submitter through Revenue Online at least 5 days before their first filing. Entities that withhold tax reported on a 1099 must also set up a separate withholding tax account with the Department of Revenue, distinct from any wage-withholding (W-2) account.

Late-filing penalties

Colorado penalty overview

Failure-to-file penalty: $5 to $50 per W-2/1099 not filed timely, at the Department's discretion (C.R.S. 39-22-604(6)(a) and Colorado Wage Withholding Tax Guide, Part 4). The penalty applies per form to filers who are required to file electronically but submit paper instead.

Late-payment penalty (when withholding tax is unpaid): the greater of $5 or 5% of the unpaid tax, plus 0.5% per month, capped at 12% total; a 15% collection penalty is added if not paid after notice and demand.

Backup withholding (C.R.S. 39-22-604(18)): if a 1099 payee fails to provide a validated TIN, or provides a nonresident-alien ITIN, the payer must withhold Colorado income tax at the section 39-22-104 / 39-22-301 rate.

Frequently asked questions

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

Colorado 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 Colorado participate in the CF/SF program?

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

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

The filing deadline is Federal e-file deadline. If the date falls on a weekend or federal holiday, the next business day generally applies.

What format does Colorado accept for 1099-INT?

Because CF/SF filing satisfies Colorado, 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 Colorado if I also filed federally?

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

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

**Failure-to-file penalty:** $5 to $50 per W-2/1099 not filed timely, at the Department's discretion (C. See the full penalty details below for the complete schedule.

How do I register to file with Colorado?

Anyone submitting W-2s, 1099s, or W-2Gs must register as a Withholding Submitter through Revenue Online at least 5 days before their first filing. See the registration section above for the full requirements.

Source citations

Verified from 3 primary sources

“Any 1099 statements you distribute that contain Colorado state withholding must be sent to the department.”

Apr 23, 2026 https://tax.colorado.gov/DR1106

“The DR 1106 Annual Transmittal of State 1099s should be filed in January for withholding taxes reported on Federal form 1099.”

Apr 25, 2026 https://tax.colorado.gov/DR1106

“Select "Submit a Withholding File Attachment," then attach your CDOR-EFW2 file or IRS Withholding file. For W-2s, the electronic file must be IRS Format 1220 or CDOR-EFW2.”

Apr 25, 2026 https://tax.colorado.gov/training/file-withholding-online

Related filing guides

Additional notes

Colorado is a participating state in the IRS Combined Federal/State Filing (CF/SF) Program for most 1099 series forms (INT, DIV, MISC, R, K, and others) — the IRS forwards those to the Colorado Department of Revenue automatically when the filer opts in at the federal level. Form 1099-NEC is a notable exception: the Department of Revenue treats 1099-NEC as a direct-file form and instructs filers to submit it through Revenue Online as a .TXT file in IRS Publication 1220 format. In addition, any 1099 that reports Colorado state tax withholding must be filed directly with Colorado regardless of CF/SF participation — those are submitted electronically through Revenue Online (or on paper accompanied by the DR 1106 transmittal). E-filing is required if the filer has 10 or more federal information returns; the DR 1106 transmittal is only required with paper filings or to remit balance due / claim a refund. The general 1099 due date with Colorado is January 31.