How to File Maine 1099 Forms: Deadlines, Portal, and Penalties

To file a 1099 in Maine, submit the return through the Maine Tax Portal at revenue.maine.gov by January 31 of the year after payment. For tax year 2025, the deadline shifts to February 2, 2026, because January 31 falls on a Saturday.¹ If you file 10 or more W-2 and 1099 forms combined at the federal level, Maine requires you to file electronically. The $600 threshold that triggers federal 1099 reporting also triggers Maine’s requirement, and $10 is the floor for interest and dividends.²

Which 1099 Forms Go to Maine

Maine wants information returns for payments made to anyone who may owe Maine income tax. In practice that covers the forms most businesses handle: 1099-NEC for contractors, 1099-MISC for rents and other miscellaneous income, 1099-R for retirement distributions, 1099-INT for interest, 1099-DIV for dividends, and 1099-G for government payments.

Maine participates in the IRS Combined Federal/State Filing program, so the IRS forwards certain 1099 data to the state and you don’t need to file those forms twice.³ The forms Maine accepts through CF/SF are 1099-DIV, 1099-B, 1099-G, 1099-INT, 1099-MISC, 1099-OID, 1099-PATR, and 1099-R.⁴ Notice what’s missing: the 1099-NEC. Contractor payments reported on 1099-NEC must be filed directly with Maine Revenue Services through the portal rather than relying on CF/SF to forward them.

If you do use CF/SF for the forms it covers, don’t also submit those same forms directly to MRS. Duplicate filings can trigger unnecessary notices.⁴

The January 31 Deadline

The statutory due date for all 1099 and W-2G information returns is January 31 of the year following the payment.² When January 31 lands on a weekend or holiday, the deadline moves to the next business day. For tax year 2025 that pushes the due date to February 2, 2026.¹

The deadline is uniform across every 1099 form type, whether you submit directly to the portal or let CF/SF carry it. Recipients need their copies by the same date so they can file their own Maine returns, so give yourself a few days of buffer.

Who Has to File Electronically

Starting with forms due in 2024, any employer or payer required to file 10 or more federal W-2 and 1099 forms in the aggregate must file them electronically with Maine Revenue Services through the Maine Tax Portal.¹ The count combines form types. Six W-2s plus four 1099-NECs puts you at the threshold.

Below 10 forms, you can still use the portal for manual entry. MRS does not appear to offer a standard paper option for 1099 forms, so even low-volume filers should plan on the portal.

One change is coming. MRS expects to adopt the IRS’s XML format for 1099 forms starting with tax year 2026, with filings due in 2027.⁵ If you use third-party software to generate bulk files, check that your vendor plans to support the new format before that transition.

What to Gather Before You File

Pull these together before logging into the portal:

Your Federal Employer Identification Number (FEIN).
Your Maine withholding account number, assigned by MRS when you register your business through the Maine Tax Portal. If you haven’t registered, you can do that at revenue.maine.gov under “Register a New Business”; the account number arrives by mail in about 20 days.
A Social Security Number or EIN for each recipient. Missing or incorrect TINs are the most common reason filings get flagged.
Gross payment totals for each recipient and the exact Maine income tax withheld, if any. These figures have to match what you reported on the federal copy.
Your Maine Tax Portal username and password. If you file withholding returns already, you likely have an account.

Verify each recipient name and TIN against the W-9 on file. A mismatch can trigger a $50 per return penalty under Maine law, and corrections after filing have to be done manually.

Submitting Through the Maine Tax Portal

Every direct filing runs through the Maine Tax Portal at revenue.maine.gov. After logging in, go to the information returns section to start.

Bulk File Upload

Filers with volume can upload a bulk data file. The file follows the IRS Publication 1220 record layout, using T, A, B, and F records, with Maine-specific modifications to the B record.⁵ A few technical rules to hand to whoever generates your file:

Plain ASCII text with a .txt extension. Compressed files are rejected.
Each record is exactly 750 bytes.
Each record ends with a carriage return, line feed, or both.
One tax year per file. Files spanning multiple years will be rejected.

Most payroll and accounting software can generate a Publication 1220 file. Before uploading, pull the current year’s MRS specification document from the bulk file upload page and spot-check any Maine-specific fields.

Manual Entry

For a handful of returns, you can key each one into the portal’s form fields and review the dollar amounts and TINs on screen before submitting. When you finish, the portal issues a confirmation number. Save or print it. That receipt is your proof of timely filing if MRS ever asks.

Fixing a Return After You File

Found an error? Wrong amount, bad TIN, missing form? You have to correct it manually through the Maine Tax Portal. MRS does not accept corrected 1099 or W-2G forms through bulk upload.¹ That holds even if you have thousands of returns to fix. The manual-only rule has been in effect since October 2023, so there’s no bulk workaround.

File corrections as soon as you catch the mistake. The longer you wait, the more likely a recipient files a Maine return using the wrong figure, which can produce matching notices for both of you.

Penalties for Missing or Botching a Filing

Maine runs its own penalties on top of anything the IRS assesses. Per return they’re modest; across many payees they add up.

$50 per return for each information return you were required to file but didn’t, or that was willfully false or fraudulent.²
A separate $50 civil penalty per return for willfully failing to furnish the recipient’s copy of the 1099 in the required form and timeframe.⁶

Both penalties apply per form. A business that fails to file and also fails to send copies for 100 payees could face $10,000 in state penalties alone, with federal penalties running separately and higher.⁷ File on time, check your recipient data against W-9s before submitting, and keep your confirmation numbers.

1
Maine Revenue Services. Electronic File Specifications Forms 1099 and W-2G Tax Year 2025
2
Maine State Legislature. Maine Code Title 36 – 5242 – Information Returns
3
Internal Revenue Service. Topic No. 804, FIRE System Test Files and Combined Federal/State Filing Program
4
Maine Revenue Services. Electronic File Specifications for Forms 1099 and W-2G
5
Maine Revenue Services. Forms 1099 and W-2G Electronic File Specifications
6
Maine State Legislature. Maine Revised Statutes Title 36 Taxation 5251-A
7
Internal Revenue Service. Information Return Penalties