Form I-9 for employers: the deadlines that matterChecked

Your new hire starts Monday. The offer is signed, the laptop is ordered, and somewhere in the pile is a Form I-9 that has two deadlines, two different people responsible, and no room for "we'll sort it out next week." Most I-9 problems aren't about hard questions. They're about timing.

This guide walks through the I-9 timeline, who fills which part, how it differs from the W-4 and W-9, and how long to keep it. For the wider picture of tax and onboarding forms, start with our W-9 vs W-8BEN guide.

What is Form I-9 and who must complete it?

Form I-9, Employment Eligibility Verification, is how US employers confirm a new hire's identity and authorization to work. USCIS says "all employers must complete and retain Form I-9" for every person hired after November 6, 1986 who works for pay. The employee completes Section 1; the employer completes Section 2.

The form is not filed with the government. You complete it, keep it, and produce it if an authorized agency asks to inspect it. Always use the current edition from the USCIS Form I-9 page (opens in a new tab); we don't quote edition dates here because they change.

The form opens with an anti-discrimination notice that's worth reading to every hiring manager: "All employees can choose which acceptable documentation to present for Form I-9. Employers cannot ask employees for documentation to verify information in Section 1, or specify which acceptable documentation employees must present for Section 2."

What are the Form I-9 deadlines?

There are two. The employee must complete and sign Section 1 no later than their first day of employment, and not before accepting the job offer. The employer must complete Section 2 within 3 business days of the first day of work for pay. Short jobs of under 3 days need Section 2 by day one.

Here is the timeline for a typical hire:

USCIS gives a clean example on its Section 2 page (opens in a new tab): "if your employee began work for pay on Monday, you must complete Section 2 by Thursday of that week."

Who fills in each section of the I-9?

The employee fills in and signs Section 1, with help from a preparer or translator if needed. The employer, or an authorized representative, completes Section 2 after examining the employee's documents. Supplement A records any preparer or translator; Supplement B, formerly Section 3, covers reverification and rehires.

A few rules from USCIS that matter in practice:

• Section 1 is the employee's. If someone helps, they complete and sign the certification on Supplement A, and the employee still signs Section 1. Keep Supplement A with the form.
• Social Security number is optional, mostly. USCIS says employees aren't required to enter it unless you participate in E-Verify.
• The employee picks the documents. One document from List A, or one from List B plus one from List C. Some receipts are acceptable in certain cases.
• Section 2 means physically examining documents. USCIS notes that employers enrolled in E-Verify may use an alternative procedure to examine documents remotely.

What is the difference between Form I-9, W-4 and W-9?

Form I-9 verifies identity and work authorization and stays in your files. Form W-4 tells you how much federal income tax to withhold from an employee's pay. Form W-9 is for contractors and vendors, not employees: it collects their taxpayer identification number. A new employee usually completes an I-9 and a W-4, not a W-9.

The IRS describes the W-4 this way on its About Form W-4 page (opens in a new tab): "Complete Form W-4 so that your employer can withhold the correct federal income tax from your pay." Our W-9 vs W-8BEN guide covers the contractor side. Hiring in Australia too? The equivalent pack is quite different: see new starter forms in Australia.

How long must I keep Form I-9?

Keep each Form I-9 for three years after the date of hire or one year after employment ends, whichever is later. Keep it for the whole time the person works for you, then calculate the date when they leave. Forms can be stored on paper or electronically, as long as you can produce them for inspection.

The USCIS Handbook for Employers, section 10.0 (opens in a new tab) gives a shortcut: if someone worked for you for less than two years, keep their form for three years after their first day of employment; if more than two years, keep it for one year after they stop working for you.

A simple retention checklist:

• Section 1, Section 2 and any supplements stored together
• Copies of documents, if you choose to keep them, stored with the form
• Separation date recorded when someone leaves
• Destruction date calculated and diarised
• Forms retrievable quickly if an inspection notice arrives

This is general information, not legal advice. An employment lawyer can advise on your specific situation, including E-Verify and remote examination.

How do I send the new-hire pack in one go?

Bundle the documents each new hire must complete into one envelope: Form I-9 Section 1, Form W-4 and your own policies. Set the employee as the first signer and HR as the second, so Section 2 is ready for you as soon as Section 1 is back. Send it the day the offer is accepted.

AppliFlo's library of official forms includes Form I-9 and Form W-4 with their fields already in place, so filling them never uses AI pages. A sensible flow:

1. Pre-fill what you already know. Name and contact details come from the candidate's record; anything missing is flagged for a person rather than guessed.
2. Send with roles. In Sign, the employee completes and signs first, then the envelope moves to HR in order.
3. Remind, don't chase. Automatic reminders go out until the employee signs.
4. File the sealed copy. Every signed PDF gets a PAdES seal, a certificate of completion and an audit trail.

AppliFlo doesn't examine identity documents and isn't an E-Verify service: Section 2 is still your team's job. What it removes is the retyping and the chasing.

For HR teams handling many hires at once, the HR solution page shows the full onboarding flow, and our guide to filling PDF forms from Excel, CSV or your CRM covers bulk onboarding for seasonal or staffing work.