How to file 1099s with IRIS

Three ways to file with IRIS

The IRIS Taxpayer Portal

Free, manual, one submission at a time. Key each return by hand or upload a CSV in the exact IRS template layout, up to 100 returns per submission. You still need a Transmitter Control Code (TCC) to sign in.

A2A (Application-to-Application)

The IRIS API. It moves Publication 5718 XML, not CSV, and it needs your own TCC, an API Client ID, an X.509 certificate, and software that builds and validates the file. Built for filers who send 100 or more returns and want their own system to do it without a human at a keyboard.

Filing through a transmitter

Someone else already holds the TCC, the certificate, and the API Client ID, and files on your behalf. You keep producing the FIRE, CSV, or Excel files you already produce. No application, no waiting on ID.me, no schema work. This is the route IRISfile files under; see the pricing.

Before you start

IRIS TCC

Every route needs one. Apply early: the IRS says to allow up to 45 days. See the full TCC application guide.

ID.me

The identity check behind the TCC application and behind IRIS Portal sign-in. Start it before you need it, not the week you file.

Payer and recipient data

EINs and SSNs formatted correctly, current addresses, and amounts already reconciled. IRIS validates on the way in, and a bad TIN or a stale ZIP blocks the upload until you fix that row.

Portal or A2A

Decide by payer count, not by return count. One or two payers, the Portal is fine at almost any volume. Many payers, the manual work per payer is the real cost, not the 100-return cap.

Step by step: the IRIS Portal CSV upload

The column names below are the exact IRS template headers for 1099-NEC and 1099-MISC, the two form types this walkthrough covers. The IRS publishes a separate template for each form type. The full field-by-field rules are in the Publication 5717 walkthrough and the IRS Template Formatting Guidelines for each form.

1. 01

   Download the current tax-year template

   Get the Portal CSV template for each form type from the IRS IRIS page, one template per form type. File 1099-NEC and 1099-MISC as separate files; a single CSV can hold only one form type and one tax year.

2. 02

   Fill the payer identity columns

   Use the exact column headers: Payer TIN Type, Payer Taxpayer ID Number, Payer Name Type, Payer Business or Entity Name Line 1, and the address block. Payer Name Type is B for a business name or I for an individual, and it decides which name columns are required.

3. 03

   Fill the recipient identity columns the same way

   Recipient TIN Type accepts SSN, EIN, ATIN, ITIN, QI-EIN, or UND. Recipient Name Type is B or I, same rule as the payer. A row with a business name but Name Type set to I gets rejected.

4. 04

   Format every TIN with the right hyphens

   An EIN is XX-XXXXXXX. An SSN, ITIN, or ATIN is XXX-XX-XXXX. An undeterminable TIN is 9 bare digits, no hyphen. Digits and dashes only, nothing else in the field.

5. 05

   Format ZIP codes as digits only, and keep the leading zero

   A domestic ZIP is exactly 5, 9, or 12 digits with no hyphen. Opening the CSV in Excel and saving it again turns a Massachusetts ZIP like 02539 into 2539, because Excel reads the column as a number. Never round-trip the file through Excel after it is built.

6. 06

   Set every checkbox column to Y or N

   2nd TIN Notice, the FATCA box on MISC, and the direct-sales box on NEC and MISC are all Y or N on every row, never blank. If you file to multiple states, Combined Federal/State Filing takes a quoted, comma-separated state list, such as "AL,CA,DE".

7. 07

   Enter amounts as plain decimals

   No dollar sign, no thousands separator, at most two digits after the decimal. Watch for a spreadsheet that silently reformatted a large number into scientific notation, since the Portal rejects that on sight.

8. 08

   Save as CSV and stop touching it in Excel

   Save the file as CSV once, from whatever tool built it, and do not reopen it in Excel to check it. Reopening and resaving is what strips leading zeros and can rewrite line endings.

9. 09

   Upload, read the error report, then submit

   The Portal validates on upload and names the failing column and row. Fix what it flags and resubmit the same file rather than starting a new one, so you know exactly what changed.

Why the Portal rejects a CSV

Almost every rejection traces back to one of these seven causes, and most of them start with a spreadsheet program touching the file after it was built.

Blank rows from doubled line endings

A file saved with \r\r\n line endings shows the Portal a blank row after every real one. The Portal reports this as "Form Type, Tax Year, and at least 1 other column must be filled in," which reads like a missing field but is really a phantom row.

Leading zeros stripped from ZIP codes

Any spreadsheet program treats a ZIP column as a number unless it is told otherwise. Round-trip the file through Excel and 02539 becomes 2539, which fails the exact-length ZIP rule on upload.

A TIN with no hyphen, or the wrong hyphen pattern

EINs and SSNs each have a fixed hyphen position. A TIN typed as nine bare digits, or hyphenated the wrong way for its type, fails validation even when every digit is correct.

A comma or period in a name or address line

Business name and address fields allow letters, numbers, a small set of punctuation, and blank space. A payer name like "SCM Sub, LLC" or an address like "5125 MacArthur Blvd., N.W." carries characters the Portal does not accept.

A name over the length limit

Business name lines cap at 40 characters. First name, middle name, last name, and suffix each cap at 20. A name that fits on a W-9 can still be too long for the column.

More than 250 records in one file

One CSV can hold up to 250 records. The separate 100-form limit applies later, when you select forms for a submission, so a 150-row file uploads fine and then takes two submissions.

The wrong tax year, or two form types in one file

Tax Year and Form Type are read from the file, not just from its name. A TY2024 template used for TY2025 returns, or NEC and MISC rows mixed in one CSV, both fail on upload.

What the Portal cannot do

The Portal has no API and a hard 100-form cap per submission. A transmitter-role TCC can put several issuers in one CSV, but every submission is still built and sent by hand, which is the real limit at volume, not the row count. The full breakdown is in the Portal limits guide.

When to move to A2A

Move to A2A, or to a transmitter who already runs it, once you file for more payers than you can key by hand each January, or once you already produce a FIRE or CSV export and do not want to retype it into the Portal. A2A trades manual entry for an XML schema and a certificate. See Publication 1220 vs 5718 for how the FIRE layout maps onto that schema, and the TCC application guide for what an A2A build needs beyond the TCC: an API Client ID and an X.509 certificate. Skip the build entirely by filing through a transmitter, which is the route IRISfile takes.

Questions

Do you need a TCC to use the free IRIS Portal?

Yes. Every route into IRIS requires a Transmitter Control Code, including the Portal. The only way to file without one is through a transmitter who files under theirs.

Can you upload a FIRE file to IRIS?

No. IRIS takes manual entry, the IRS CSV template through the Portal, or Publication 5718 XML through A2A. A Publication 1220 fixed-width FIRE file has to be converted to one of those first.

Can you use Excel to fill the Portal template?

Yes, to build the file. Fill the template in Excel if that is easiest, then save as CSV once and stop. Reopening the saved CSV in Excel and saving it again is what strips leading ZIP zeros and can corrupt line endings.

What does the Portal's 100-return limit actually mean?

It is a per-submission cap, not an annual one. You can send as many submissions as you need. The real cost at volume is the manual work of one submission per payer, not the 100-row ceiling.

Can you file a correction through the IRIS Portal?

Yes. IRIS lets you correct an individual record without resending the whole original file, which is an improvement over FIRE.

What happens to FIRE filing after November 19, 2026?

The IRS stops accepting production files through FIRE at 3 p.m. ET on November 19, 2026. After that, IRIS is the only electronic path for current-year returns, prior-year returns, and corrections.