Form SS-4 at a glance
| Official title | Application for Employer Identification Number |
| Issued by | Internal Revenue Service (IRS) |
| Edition | December 2025 |
| Pages | 2 |
| Fillable fields | 89: 45 text fields, 44 checkboxes |
| OMB number | 1545-0003 |
| Official PDF | fss4.pdf on irs.gov |
| Form page | irs.gov/forms-pubs/about-form-ss-4 |
| Cost with FillWise | 1 fill |
Counted on Oct 1, 2026 from the official PDF, with the same engine FillWise fills it with.
How to fill Form SS-4 with FillWise
- Download the official PDF from irs.gov and open it in a Chrome tab.
- Open the FillWise side panel and paste what you know in any shape: notes, an email, a questionnaire. You can also attach a photo or scan of a document, such as a passport bio page, and FillWise reads it together with the text.
- Press Fill form. The completed PDF downloads under its original file name.
- Open it in your PDF reader and check every page before anyone signs.
To redo only part of the form, Which pages to fill in the panel limits the fill to the pages you pick.
No extension? On your account page, Fill a PDF does the same in any browser: upload the form, paste the data, review the result and download it.
How FillWise handles Form SS-4
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.
The file also carries Adobe XFA data next to its regular form fields. FillWise fills the regular fields and leaves the XFA part out, so the result opens in Acrobat, Preview or Chrome alike.
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-ss-4.
- Names and numbers, character by character. Names exactly as in the ID document, and every ID, tax or case number.
- Signatures. FillWise signs nothing; signing and dating the form is yours.
- Everything outside the form. Fees, where to send it and supporting documents are not part of the fill.
Cost
Form SS-4 has 2 pages, but its fields are on page 1 only, 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
With the extension, the PDF is opened and filled inside your browser. What goes to our server for AI processing is the list of the form's fields and the data you pasted or attached, and none of it is stored after the fill. The full picture is on our privacy and security page.