Every employer in the United States has to complete a Form I-9 for every person it hires, whether that person is a U.S. citizen or not. The form itself is short. The rules around it fill a government handbook.
That gap is where small businesses get hurt. In our experience, most I-9 problems aren't about hiring people who can't legally work. They're paperwork errors: a missed deadline, a blank field, a form kept too long or shredded too early. Each one can carry its own penalty, and they add up quickly across a workforce.
Here are the seven mistakes we see most often.
1. Completing Section 2 late
The employee completes Section 1 no later than their first day of work. The employer then has three business days from that first day to examine the employee's documents and complete Section 2.
Late Section 2s are one of the most common audit findings, usually because onboarding happened in a rush or the person who handles I-9s was out. Build the deadline into your onboarding checklist and assign a backup.
2. Telling employees which documents to bring
Employees choose which acceptable documents to present: one document from List A, or one from List B plus one from List C. Asking a new hire specifically for a driver's license and Social Security card, or asking a noncitizen for a green card, can be treated as discrimination even when you mean well.
The safe practice is to give every new hire the official Lists of Acceptable Documents and let them choose.
3. Using an outdated version of the form
USCIS periodically releases new editions of Form I-9 and sets a date after which older versions can't be used. As of this writing, the current edition is dated 01/20/25. Check the edition date printed at the bottom of the form before each hire, or download a fresh copy from uscis.gov.
4. Leaving fields blank
Missing signatures, missing dates, a blank document expiration date, a missing first day of employment: each is a technical violation. A few Section 1 fields, such as email and phone number, are optional. Most of the rest are not.
Before you file any I-9, read every field in Sections 1 and 2 and confirm nothing required is empty.
5. Missing reverification deadlines
When an employee's work authorization has an expiration date, you have to reverify it before it expires, using Supplement B of the form. A shared calendar with reminders is enough for most small employers.
Just as important, don't reverify what doesn't need it. U.S. citizens and noncitizen nationals never need reverification, and you shouldn't reverify List B identity documents or a Permanent Resident Card. Over-reverifying creates its own discrimination risk.
6. Keeping forms for the wrong amount of time
The retention rule: keep each I-9 for three years after the date of hire, or one year after employment ends, whichever is later. For current employees, that means keeping the form for as long as they work for you.
Businesses tend to get this wrong in both directions: shredding former employees' forms too early, or keeping every I-9 forever. Holding forms past their retention date only gives an inspector more paperwork to review, so purge them on a schedule. It also helps to store I-9s separately from personnel files, so an inspection doesn't expose unrelated records.
7. Fixing errors the wrong way
When you find a mistake, how you fix it matters as much as the mistake. Don't backdate, don't use correction fluid, and don't quietly redo the form and throw away the original.
Instead, draw a line through the incorrect information, write the correct information nearby, and initial and date the change. Errors in Section 1 should be corrected by the employee. If a form is missing entirely for a current employee, complete one now using the current date, and keep a short signed, dated note explaining what happened.
What an inspection can cost
A Notice of Inspection from Immigration and Customs Enforcement gives an employer at least three business days to produce its I-9s. That isn't enough time to fix years of errors.
Civil penalties for paperwork violations are assessed per form. For penalties assessed in 2025, the range was $288 to $2,861 per form, and the amounts are adjusted for inflation each year. Knowingly hiring or continuing to employ unauthorized workers carries substantially higher penalties.
How to get ahead of it
A self-audit catches most of these problems while they're still cheap to fix:
- List every current employee, plus every former employee whose I-9 you're still required to keep.
- Confirm you have an I-9 for each one.
- Review each form against the seven mistakes above.
- Correct errors the right way, and document what you did.
- Fix the process that caused the errors, not only the forms.
Some businesses run the audit through legal counsel so the findings are privileged. Either way, review a sample every year, and the full set whenever the person who handles onboarding changes.