IRIS 1098 CSV template and checker
Form 1098, Mortgage Interest Statement, can be filed in the IRIS Taxpayer Portal with a CSV upload. Its template has 54 columns, 15 of them required, including 11 form box columns. Drop your file below to check it against every IRS rule, or read the column list further down.
Free. Checks every column against the IRS formatting guidelines.
2What the check found
3Download fixed files
Download the blank 1098 header (CSV) All IRIS templates
Built from the IRS TY2025 Template Formatting Guidelines, the latest posted. IRIS checks the header row against the template you download inside the portal, so upload with that one. Columns marked required are starred in the IRS guidelines.
Upload limits for every IRIS CSV
- Up to 250 records per file, header not counted, and files of 100KB or less.
- One form type and one tax year per file.
- Save as CSV UTF-8, and do not reopen and re-save the file in Excel.
- Leave money cells empty instead of 0.00, and enter Y or N in every checkbox column.
All 54 columns
| Col. | Field | Required | Example | Formatting rules |
|---|---|---|---|---|
| A | Form Type | 1098 | ||
| B | Tax Year | 2024 | ||
| C | Lender TIN Type | Yes | SSN | Must be entered as "SSN" and "EIN" |
| D | Lender Taxpayer ID Number | Yes | 123-23-1234 | Digits and dashes only Business TINs (EIN) must be in XX-XXXXXXX format Individual TINs (SSN) must be in XXX-XX-XXXX format |
| E | Lender Name Type | Yes | B | Must be entered as "B" for Business Name or "I" for Individual |
| F | Lender Business or Entity Name Line 1 | Yes | John Finch Company | Required if Name Type = "B" Length: Max 40 characters May only contain alphabet letters, numbers, blank space (), and the following special characters: hyphen (-), pound (#), parentheses (), ampersand (&), and apostrophe (') May not contain leading, trailing, and adjacent spaces |
| G | Lender Business or Entity Name Line 2 | Length: Max 40 characters May only contain alphabet letters, numbers, blank space (), and the following special characters: hyphen (-), pound (#), parentheses (), ampersand (&), apostrophe ('), slash (/), and percent (%) May not contain leading, trailing, and adjacent spaces | ||
| H | Lender First Name | John | Required if Name Type = "I" Required if Last Name is filled out Length: Max 20 characters May only contain alphabet letters, blanks ( ) and hyphens (-) May not contain leading, trailing, and adjacent spaces | |
| I | Lender Middle Name | James | Length: Max 20 characters May only contain alphabet letters, blanks ( ) and hyphens (-) May not contain leading, trailing, and adjacent spaces | |
| J | Lender Last Name (Surname) | Finch | Required if Name Type = "I" Required if First Name is filled out Length: Max 20 characters May only contain alphabet letters, blanks ( ) and hyphens (-) May not contain leading, trailing, and adjacent spaces | |
| K | Lender Suffix | Length: Max 20 characters May only contain alphabet letters, blanks ( ) and hyphens (-) May not contain leading, trailing, and adjacent spaces | ||
| L | Lender Country | Yes | US | Must be entered according to their designated country abbreviation Link to country abbreviations: https://www.irs.gov/e-file- providers/foreign-country-code-listing-for-modernized-e-file |
| M | Lender Address Line 1 | Yes | 1234 Midway Rd | Length: Max 35 characters May only be alpha-numeric characters and the following special characters: hyphen ( - ) slash ( / ) space ( ) May not contain leading, trailing, and adjacent spaces |
| N | Lender Address Line 2 | Length: Max 35 characters May only be alpha-numeric characters and the following special characters: hyphen ( - ) slash ( / ) space ( ) May not contain leading, trailing, and adjacent spaces | ||
| O | Lender City/Town | Yes | Dallas | Length: Max 40 characters May only be alphabet characters and the following special characters: space ( ) May not contain leading, trailing, and adjacent spaces |
| P | Lender State/Province/Territory | Yes | Texas (TX) | [Domestic] Must be entered as their 2 letter abbreviation Link to 2 letter abbreviation: https://www.irs.gov/pub/irs- utl/zip code and state abbreviations.pdf _ _ _ _ [Foreign] Length: Max 17 characters Alpha-numeric characters (A-Z, 0-9) and spaces only May not contain leading, trailing, and adjacent spaces |
| Q | Lender ZIP/Postal Code | Yes | 12309 | [Domestic] Length: Exactly 5, 9 or 12 characters Digits only [Foreign] Length: Max 9 characters Alpha-numeric characters only (A-Z, 0-9) |
| R | Lender Phone Type | D | Must be entered as "D" for Domestic or "I" for International | |
| S | Lender Phone | 2145555555 | Domestic Phone must be in one of the following formats: 1231231234, 123-123-1234, (123) 123-1234 International Phone must be 15 digits or less and may only include the "+" symbol at the beginning | |
| T | Borrower TIN Type | SSN | Required if TaxBorrower ID Number is entered. Must be entered as "SSN", "EIN", "ATIN", "ITIN", "QI-EIN", or "UND" | |
| U | Borrower Taxpayer ID Number | 123-23-1234 | Business TINs (EIN, QI-EIN) must be in XX-XXXXXXX format Individual TINs (SSN, ITIN, ATIN) must be in XXX-XX-XXXX format Undeterminable TINs (UND) must be in XXXXXXXXX format | |
| V | Borrower Name Type | Yes | B | Must be entered as "B" for Business Name or "I" for Individual |
| W | Borrower Business or Entity Name Line 1 | ABC123 | Required if Name Type = "B" Length: Max 40 characters May only contain alphabet letters, numbers, blank space (), and the following special characters: hyphen (-), pound (#), parentheses (), ampersand (&), and apostrophe (') May not contain leading, trailing, and adjacent spaces | |
| X | Borrower Business or Entity Name Line 2 | Length: Max 40 characters May only contain alphabet letters, numbers, blank space (), and the following special characters: hyphen (-), pound (#), parentheses (), ampersand (&), apostrophe ('), slash (/), and percent (%) May not contain leading, trailing, and adjacent spaces | ||
| Y | Borrower First Name | Sarah | Required if Name Type = "I" Required if Last Name is filled out Length: Max 20 characters May only contain alphabet letters, blanks ( ) and hyphens (-) May not contain leading, trailing, and adjacent spaces | |
| Z | Borrower Middle Name | Jasmin | Length: Max 20 characters May only contain alphabet letters, blanks ( ) and hyphens (-) May not contain leading, trailing, and adjacent spaces | |
| AA | Borrower Last Name (Surname) | Finch | Required if Name Type = "I" Required if First Name is filled out Length: Max 20 characters May only contain alphabet letters, blanks ( ) and hyphens (-) May not contain leading, trailing, and adjacent spaces | |
| AB | Borrower Suffix | Length: Max 20 characters May only contain alphabet letters, blanks ( ) and hyphens (-) May not contain leading, trailing, and adjacent spaces | ||
| AC | Borrower Country | Yes | US | Must be entered according to their designated country abbreviation Link to country abbreviations: https://www.irs.gov/e-file- providers/foreign-country-code-listing-for-modernized-e-file |
| AD | Borrower Address Line 1 | Yes | 1234 Midway Rd | Length: Max 35 characters May only be alpha-numeric characters and the following special characters: hyphen ( - ) slash ( / ) space ( ) May not contain leading, trailing, and adjacent spaces |
| AE | Borrower Address Line 2 | Length: Max 35 characters May only be alpha-numeric characters and the following special characters: hyphen ( - ) slash ( / ) space ( ) May not contain leading, trailing, and adjacent spaces | ||
| AF | Borrower City/Town | Yes | Dallas | Length: Max 40 characters May only be alphabet characters and the following special characters: space ( ) May not contain leading, trailing, and adjacent spaces |
| AG | Borrower State/Province/Territory | Yes | TX | [Domestic] Must be entered as their 2 letter abbreviation Link to 2 letter abbreviation: https://www.irs.gov/pub/irs- utl/zip code and state abbreviations.pdf _ _ _ _ [Foreign] Length: Max 17 characters Alpha-numeric characters (A-Z, 0-9) and spaces only May not contain leading, trailing, and adjacent spaces |
| AH | Borrower ZIP/Postal Code | Yes | 12309 | [Domestic] Length: Exactly 5, 9 or 12 characters Digits only [Foreign] Length: Max 9 characters Alpha-numeric characters only (A-Z, 0-9) |
| AI | Office Code | 1234 | Length: Exactly 4 digits | |
| AJ | Form Account Number | ABC12345 | Length: Max 20 characters May not be the same as the Payer or Recipient Taxpayer ID Number | |
| AK | Box 1 - Mortgage interest received from payer(s)/borrower(s) | 1000.00 | $0 to $999,999,999,999,999 Cannot be negative Digits only except 1 decimal is allowed Must have no more than two digits after the decimal. Check for long numbers in money amount fields that may have been formatted in scientific notation. For example: 1.045E+5. | |
| AL | Box 2 - Outstanding Mortgage Principal | 2000 | $0 to $999,999,999,999,999 Cannot be negative Digits only except 1 decimal is allowed Must have no more than two digits after the decimal. Check for long numbers in money amount fields that may have been formatted in scientific notation. For example: 1.045E+5. | |
| AM | Box 3 - Mortgage Origination Date | 03/30/2022 | Length: Max 8 characters Digits only Date field must be in MM/DD/YYYY format Must fall within the tax year the form is being prepared for. | |
| AN | Box 4 - Refund of Overpaid Interest | 500.50 | $0 to $999,999,999,999,999 Cannot be negative Digits only except 1 decimal is allowed Must have no more than two digits after the decimal. Check for long numbers in money amount fields that may have been formatted in scientific notation. For example: 1.045E+5. | |
| AO | Box 5 - Mortgage Insurance Premiums | $0 to $999,999,999,999,999 Cannot be negative Digits only except 1 decimal is allowed Must have no more than two digits after the decimal. Check for long numbers in money amount fields that may have been formatted in scientific notation. For example: 1.045E+5. | ||
| AP | Box 6 - Points Paid on Purchase of Principal Residence | $0 to $999,999,999,999,999 Cannot be negative Digits only except 1 decimal is allowed Must have no more than two digits after the decimal. Check for long numbers in money amount fields that may have been formatted in scientific notation. For example: 1.045E+5. | ||
| AQ | Box 7 - Same Payer Address | Length: Max 1 character Must be entered as "Y" for Yes or "N" for No | ||
| AR | Box 8 - Address or Description of Property Securing Mortgage | Transferor Address section header, not to be filled out by user. | ||
| AS | Country | US | Must be entered according to their designated country abbreviation. | |
| AT | Address Line 1 | 1234 Midway Rd | Length: Max 35 characters May only be alpha-numeric characters and the following special characters: hyphen ( - ) slash (/) single space ( ) Must be less than or equal to 35 characters. May not contain leading, trailing, and adjacent spaces If at least 1 domestic address field is filled out, it should include Country, Address Line 1, City/Town, State/Province/Territory, and ZIP/Postal code. Foreign addresses must include Country and Address Line 1. | |
| AU | Address Line 2 | Unit 123 | Length: Max 35 characters May only be alpha-numeric characters and the following special characters: hyphen ( - ) slash (/) single space ( ) Must be less than or equal to 35 characters. May not contain leading, trailing, and adjacent spaces If at least 1 domestic address field is filled out, it should include Country, Address Line 1, City/Town, State/Province/Territory, and ZIP/Postal code. Foreign addresses must include Country and Address Line 1. | |
| AV | City/Town | Midway | Length: Max 40 characters May only be alphabet characters and the following special characters: space ( ) Must be less than or equal to 40 characters. May not contain leading, trailing, and adjacent spaces If at least 1 domestic address field is filled out, it should include Country, Address Line 1, City/Town, State/Province/Territory, and ZIP/Postal code. Foreign addresses must include Country and Address Line 1. | |
| AW | State/Province/Territory | VA | Length: Max 2 characters Must be be entered as their 2 letter abbreviation. Link to 2 letter abbreviation: https://www.irs.gov/pub/irs- utl/zip code and state abbreviations.pdf _ _ _ _ May not contain leading, trailing, and adjacent spaces If at least 1 domestic address field is filled out, it should include Country, Address Line 1, City/Town, State/Province/Territory, and ZIP/Postal code. Foreign addresses must include Country and Address Line 1. [Foreign] Length: Max 17 characters Must be less than or equal to 17 characters. Alpha-numeric characters (A-Z, 0-9) and spaces only May not contain leading, trailing, and adjacent spaces | |
| AX | ZIP/Postal Code | 12345 | [Domestic] Length: Exactly 5, 9 or 12 characters Digits only If at least 1 domestic address field is filled out, it should include Country, Address Line 1, City/Town, State/Province/Territory, and ZIP/Postal code. Foreign addresses must include Country and Address Line 1. [Foreign] Length: Max 9 characters Alpha-numeric characters only | |
| AY | Provide a Legal Description | Length: Max 861 characters Address or Description of Property Securing Mortgage is required if Box 7 - Same Payer Address is unchecked. Should only include alphanumeric values and certain special characters and may not include leading or trailing spaces, or more than 1 space in a row. Allowed special characters include the following: ! " # $ % & ' ( ) * + , - . / : ; < > = ? @ { | } ~ £ § Á É Í Ñ Ó × Ú Ü á é í ñ ó ú ü | ||
| AZ | Box 9 - Number of Properties Securing the Mortgage | 123 | Length: Max 10 characters Must be integer(s) | |
| BA | Box 10 - Other | Length: Max 150 characters Should only include alphanumeric values and certain special characters and may not include leading or trailing spaces, or more than 1 space in a row. Allowed special characters include the following: ! " # $ % & ' ( ) * + , - . / : ; < > = ? @ { | } ~ £ § Á É Í Ñ Ó × Ú Ü á é í ñ ó ú ü | ||
| BB | Box 11 - Mortgage Acquisition Date | 03/30/2023 | Length: Max 8 characters Digits only Date field must be in MM/DD/YYYY format Must fall within the tax year the form is being prepared for. |
What the checker does
- Header: reports missing, extra or reordered columns compared with the 1098 template.
- Safe fixes: trims stray spaces, writes amounts as plain numbers, leaves $0 cells empty, fills empty Y/N boxes with N, adds dashes to TINs from the TIN type, restores ZIP leading zeros, converts state names to codes and rewrites dates.
- Errors to fix yourself: required columns left empty, values over the length limit, codes that are not in the allowed list, invalid TINs, ZIP codes and dates.
- Split: writes files of up to 250 records and under 100KB, keeping your header row.
Date columns: the IRS guidelines ask for MM/DD/YYYY but also say "Max 8 characters, Digits only". The checker accepts both MM/DD/YYYY and MMDDYYYY. If the portal rejects one, try the other.
For 1099-NEC and 1099-MISC, the main IRIS CSV tool goes further: it builds the template from QuickBooks, Excel or FIRE files.
Frequently asked questions
Where do I download the official 1098 CSV template?
Sign in to the IRIS Taxpayer Portal, open Upload CSV with Form Data, choose 1098 and the tax year, and select Download. The formatting guidelines are linked in the FAQ box on the same page.
How many 1098 records can one CSV hold?
Up to 250 records per file, not counting the header, and the file must be 100KB or less. The portal then submits at most 100 forms at a time.
What does "required" mean here?
The IRS guidelines mark these columns with an asterisk. Other columns can still become required by a rule, for example a TIN type when a TIN is entered.
Sources
- IRS: TY2025 IRIS CSV Template Formatting Guidelines (ZIP)
- IRS Publication 5717, IRIS Taxpayer Portal User Guide (Rev. 9-2026)
Last reviewed November 1, 2026.