Form 1040-X at a glance
| Official title | Amended U.S. Individual Income Tax Return |
| Issued by | Internal Revenue Service (IRS) |
| Edition | December 2025 |
| Pages | 2 |
| Fillable fields | 166: 123 text fields, 43 checkboxes |
| OMB number | 1545-0074 |
| Official PDF | f1040x.pdf on irs.gov |
| Form page | irs.gov/forms-pubs/about-form-1040x |
| Cost with FillWise | 1 fill |
Counted on Oct 11, 2026 from the official PDF, with the same engine FillWise fills it with.
What Form 1040-X asks for
- Page 1: This return is for calendar year (enter year), Last name, Your social security number, If joint return, spouse’s first name and middle initial, Spouse’s social security number, Home address (number and street), Apt, City, town, or post office, State, ZIP code and more.
- Page 2: Correct number, Dependent 2, Dependent 3, Dependent 4, Last name, SSN, Relationship, Child tax, Explanation of Changes, Your occupation and more.
The captions printed next to the first fields of each page, as the PDF gives them.
Fields to watch on Form 1040-X
- 4 questions answered with a Yes box. FillWise ticks one only when your notes answer it; the rest stay empty for you.
- 12 boxes with a fixed number of characters, such as This return is for calendar year (enter year) (4), Your social security number (9), Spouse’s social security number (9), Amount of line 21 you want applied to your (enter year) (4). Long numbers are split across them, so check the digits.
- 1 box for a written answer, such as Explanation of Changes. FillWise writes it from your notes, so read every sentence before the form is signed.
How to fill Form 1040-X with FillWise
- Open the official PDF from irs.gov in Chrome.
- In the FillWise side panel, paste your notes or attach a photo of a document, and press Fill form.
- Check all 2 pages of the downloaded PDF before anyone signs.
Without the extension: Fill a PDF in your account.
How FillWise handles Form 1040-X
FillWise fills this form the regular way: the AI reads each field's printed caption, its tooltip and its options, and answers from your notes.
It also carries Adobe XFA data; FillWise fills the regular fields and drops the XFA part, so the result opens in any reader.
What to check before you file
- The edition. Agencies replace their forms with new editions. This page describes the December 2025 edition; check that your copy is still the current one on irs.gov/forms-pubs/about-form-1040x.
- FillWise copies the amounts in your notes into columns A, B and C; it does not work out the net change or the tax. Check each line's arithmetic, and that Part II explains every change.
- Names and numbers character by character; signatures, fees and supporting documents stay with you.
Filling Form 1040-X for many people
Bulk fill in your FillWise account takes Form 1040-X and a CSV or Excel sheet with one person per row. It fills the first one and stops so you can check the result, then fills the rest and hands back one zip. Each copy costs 1 fill, the same as filling it on its own. How it works step by step: bulk PDF form filling guide.
Cost
Form 1040-X has 2 pages, so filling it costs 1 fill: FillWise charges a PDF fill by the pages it fills, one fill per started 5 pages. The free plan starts with 20 fills and then tops back up to 5 fills a week, no card required. Paid plans are on the pricing page.
Privacy
The PDF is filled in your browser; only its field list and your data go to our server for the AI, and nothing is stored. Details: privacy and security.