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Convert IRS FIRE 1099 Text Files to IRIS 1099 CSV Format with W2 Mate: Complete Tutorial

Learn how to convert IRS FIRE text files (publication 1220 format for 1099s) to IRIS-compatible CSV format, using W2 Mate. This guide covers format differences, best practices, and troubleshooting for a seamless transition to the IRS Information Returns Intake System (IRIS).

IRS FIRE vs. IRIS CSV: Format Overview

IRS FIRE (Filing Information Returns Electronically) is the long-standing 1099 e-Filing format that is being phased out. It uses fixed-width, plain text files (usually 750 characters per line), with record types like T, A, B, C, K, and F. Formatting must be exact, with no headers or delimiters. IRS FIRE files are highly technical and not meant for manual editing. You must use specialized 1099 tax software, such as W2 Mate, to properly create or import the data.
IRIS CSV is the newer, spreadsheet-friendly 1099 e-File format accepted by the IRS IRIS portal. It uses comma-separated values (CSV) with required column headers, one row per recipient/form, and can be edited or reviewed in applications like Excel or Google Sheets. There is a 100-record-per-file upload limit (the limit is expected to increase to 250 in the 2026 filing season). The IRS has strict template formatting guidelines for each field in an IRIS file; for example, the “Recipient Business or Entity Name” must not exceed 40 characters and may only include alphabet letters, numbers, spaces, and certain special characters such as the hyphen (-), pound (#), parentheses (), ampersand (&), and apostrophe ('). Additionally, it may not contain leading, trailing, or adjacent spaces.

Step-by-Step Guide: Convert IRS FIRE to IRIS CSV in W2 Mate

1. Import the IRS FIRE Text File

• Open W2 Mate and select the intended form type, such as 1099-NEC.
• Go to Import and select the Form 1099 Electronic Filing Format (Publication 1220 Format) option.
• Browse and upload your FIRE file. W2 Mate will parse the fixed-width file and show a grid with the different fields for each form, such as the recipient name, TAX ID, and money amounts.

2. Review and Edit Imported Data

• Use the data grid in W2 Mate to examine imported records for accuracy.
• Edit details directly, including recipient names, TINs, amounts, and addresses.
• Add, delete, or correct records as necessary. Always save your progress.

3. Export to IRIS-Compatible CSV

• Click on E-Filing > IRIS CSV Upload > Export [Form Type] Data as IRIS Template File.
• Set the export location and filename. W2 Mate creates the IRIS CSV file with correct column order.
• For >100 records, multiple CSVs are generated automatically.

4. Verify and Correct the IRIS CSV File

• Open the exported CSV in Excel or Google Sheets.
• Review the data in the IRIS CSV file to ensure all records are accurate.
• Most likely, you will not need to make any changes to the file. However, if you do make changes, be sure to save it without altering the format (keep it as CSV UTF-8 Comma Delimited).

5. Upload to the IRS IRIS Portal

• At this point, you have successfully converted the IRS FIRE text file to an IRIS CSV file and are ready to upload it to the IRIS portal.
• Go to the IRS IRIS portal and log in with your credentials.
• Click Upload CSV with Form Data, then browse for and select your completed CSV file.
• Submit and monitor for errors. If issues are found, consult the IRS IRIS Template Formatting Guidelines and make corrections in a text editor if needed.

Please note that as of this writing (September 2025), W2 Mate software is the only software capable of converting IRS FIRE files to IRIS CSV files and allowing users to make any changes or updates during the conversion.

Best Practices & Troubleshooting

• Always keep backups of both the converted FIRE text files and the resulting IRIS CSV files for safety and data integrity.
• Always keep your W2 Mate software up to date and back up your company files to an external or cloud drive.
• If you edit the IRIS CSV file generated by W2 Mate, be careful not to break any formatting or change the file type. Always save the file in CSV format and ensure the column order, headers, and data types remain exactly as required by the IRS IRIS specifications. Editing in spreadsheet programs like Excel is possible, but take care that formatting, special characters, and file type are preserved—otherwise, your upload may be rejected by the IRIS portal.
• If unexpected errors occur, reference the official IRS template for your form type each reporting year.
• If you have a lot of records (more than the IRIS threshold per file), W2 Mate will create multiple files. Make sure to upload all files.
• If the input FIRE text file has missing data for one or more recipients, such as amounts or addresses, this information can be manually added inside W2 Mate before converting the data to the IRIS CSV format.
• If you have any questions about the IRS FIRE format, you can call the IRS at 866-455-7438. For questions about the IRIS CSV format, call 866-937-4130. For questions about the W2 Mate software and how to convert from the FIRE format to the IRIS CSV format, please contact our support team at 1-800-507-1992.
• If the source data comes from multiple sources—not just the IRS FIRE format, but also formats like Excel spreadsheets or Microsoft Dynamics GP—you can import data from these different sources into W2 Mate. After importing, you can create the resulting IRIS CSV file(s).