Form I-9 is the USCIS form every US employer must complete for every person they hire, citizens included, to verify identity and permission to work. The employee completes Section 1 by their first day of work, and you complete Section 2 within three business days of their start date after examining their original, unexpired documents.
It's one of the first jobs when you hire your first employee and one of the easiest to get wrong, mostly because people treat it like a tax form. It isn't. You never send it anywhere: USCIS says never to mail Form I-9 to USCIS or Immigration and Customs Enforcement. You keep it on file and produce it if you're inspected.
The two deadlines that matter
| Part of the form | Who completes it | Deadline |
|---|---|---|
| Section 1: Employee Information and Attestation | The new employee | No later than their first day of employment |
| Section 2: Employer Review and Verification | You or your authorised representative | Within three business days of the date employment begins |
| Section 2 for a job lasting under three business days | You | No later than the first day of employment |
| Supplement A | Anyone who helped the employee fill in or translate Section 1 | When they help |
| Supplement B | You | When you rehire someone or their work authorisation needs reverifying |
The M-274 handbook gives the example: if an employee starts on a Monday, you must review their documents and complete Section 2 on or before Thursday of that week. It also says you may terminate an employee who doesn't present acceptable documents, or an acceptable receipt, within three business days of starting.
Which documents an employee can show
The employee chooses, not you. USCIS says employees may present either one document from List A, or one from List B plus one from List C, and the M-274 handbook is blunt that you can't specify which documents they bring:
- List A shows both identity and work authorisation, so one document is enough. Some List A documents only count when presented together.
- List B shows identity only.
- List C shows work authorisation only.
If an employee hands you a List A document, don't ask for List B or C as well, and vice versa. Asking for more or different documents than the form requires is where good intentions turn into a discrimination complaint. Your job is to check that each document reasonably appears to be real and relates to the person in front of you, then record its title, issuing authority, number and expiry date.
The awkward cases the handbook covers
- A restricted Social Security card isn't an acceptable List C document. Ask for a different List C document or a List A document.
- Under-18s who can't show a List B identity document: a parent or legal guardian completes Section 1 for them plus the Supplement A certification, and the minor then shows only a List C document.
- Automatically extended work permits: an EAD automatically extended by a Federal Register notice or receipt notice counts as unexpired for Form I-9.
- E-Verify employers must make sure a List B document has a photograph if the employee uses the List B plus List C route.
Can you check documents over video?
Only if you use E-Verify. USCIS says employers enrolled in E-Verify in good standing may examine documents remotely under a DHS-authorised alternative procedure, must tick the box on the form to show they did, and must keep copies of the documents. If you offer it at a hiring site, you have to offer it consistently to every new employee at that site. Everyone else examines the original documents in person, with the employee there.
Which edition of Form I-9 to use
Check the dates printed on the form. USCIS lists the current edition with an expiry date of 31 May 2027, and says employers using an electronic I-9 must update their systems to that version by 31 July 2026. USCIS says all the pages must come from the same edition, with the edition date and page numbers visible at the bottom of each page.
Some employers must go a step further and run checks online, as our E-Verify guide explains.
How long to keep each I-9
For as long as the person works for you, and then for whichever is later: three years after their first day, or one year after their employment ends. USCIS's shortcut is simple:
- Worked for you less than two years: keep it for three years from the first day of employment.
- Worked for you more than two years: keep it for one year after the date they left.
- Never throw away a current employee's I-9 or the document copies attached to it, even if they leave days after starting.
A good HR system for a small business will diary those destruction dates for you, and some small business payroll tools can store the form alongside the employee record. Electronic storage is allowed, but USCIS warns that failing to meet DHS standards for electronic forms can bring fines.
My verdict
Build the I-9 into your onboarding checklist on day one, not as an afterthought in week two. Let the employee choose their documents, record exactly what you saw, file the form somewhere you can find it in an inspection, and diary the date it can be destroyed. That's the whole job, and it's far easier on time than in a hurry before an inspection.
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Alongside eligibility checks, every new hire completes a tax withholding form, and our guide to the withholding form shows how.
Frequently asked questions
Do US citizens need to fill out Form I-9?
Yes. USCIS says employers must complete Form I-9 for every individual they hire for employment in the United States, including citizens.
When is Section 2 of Form I-9 due?
Within three business days of the date employment begins, or by the first day if the job lasts less than three business days.
Can I ask a new hire for a specific document?
No. The M-274 handbook says you can't specify which acceptable documents an employee presents.
Where do I send a completed Form I-9?
Nowhere. You keep it on file. USCIS says never to mail Form I-9 to USCIS or ICE.
How long do I keep an I-9 after someone leaves?
Three years after their first day of work or one year after employment ends, whichever is later.
What if a new hire can't show documents within three business days?
The M-274 handbook says you may terminate an employee who fails to present acceptable documents, or an acceptable receipt, within three business days of starting.
Can I check I-9 documents remotely?
Only if you're enrolled in E-Verify in good standing and follow the DHS-authorised alternative procedure, including keeping document copies.
