What Is an I-9 Form? Your Guide to Employment Eligibility Verification

Hiring a new employee comes with legal responsibilities, and one of the most important is completing Form I-9.

The I-9 is a federally required form that verifies a new hire’s identity and authorization to work in the United States, and every U.S. employer must complete one for each employee. Missing deadlines or making errors with these forms can lead to penalties, which makes understanding the process essential.

This blog post is offered for general information purposes only. It does not constitute, and is not a substitute for, legal or tax advice.

What is an I-9 form used for?

Form I-9 is officially called the Employment Eligibility Verification form and confirms two vital things when onboarding a new employee:

• The employee’s identity

• The employee’s authorization to work in the United States

The requirement was established under the Immigration Reform and Control Act of 1986 (IRCA). Since then, employers have been legally required to verify employment eligibility for every person hired after November 6, 1986.

The official form and instructions are available from U.S. Citizenship and Immigration Services (USCIS).

Who must complete Form I-9?

All individuals hired to perform labor or services in the United States for wages or other remuneration must complete an I-9, regardless of their citizenship or immigration status. This requirement applies broadly across employment categories.

This includes:

• U.S. citizens

• Permanent residents

• Temporary workers

• Non-citizen nationals

Independent contractors generally do not complete Form I-9. However, worker misclassification can expose employers to fines and penalties.

The employee completes Section 1. The employer (or an authorized representative) completes Section 2.

How does an I-9 form work?

Form I-9 is structured in three sections, and each plays a specific role in verifying employment eligibility. The process confirms identity and work authorization, and creates a record that employers must retain in case of an audit.

Here’s how each section works.

Section 1: Employee information and attestation

The employee completes Section 1 no later than their first day of work. Section 1 captures the employee’s biographical information and requires them to attest, under penalty of perjury, to their citizenship or immigration status.

Employees must provide:

• Full legal name

• Address

• Date of birth

• Citizenship or immigration status

• Signature and date

They must also provide a Social Security number if the employer participates in E-Verify. Email address and phone number are optional fields. Even small errors, such as missing dates or unchecked boxes, can create compliance issues later.

Section 2: Employer review and verification

Section 2 shifts responsibility to the employer. It must be completed within three business days of the employee’s first day of employment for pay.

During this step, the employer must:

• Examine original identity and work authorization documents

• Record document details

• Certify that the documents appear genuine and relate to the employee

Employers are not expected to be document experts. However, they must review documents in good faith and ensure they meet federal requirements.

The full list of acceptable documents is available from USCIS in its official Form I-9 guidance. Employers may not specify which documents an employee must present; the employee chooses from the list.

Section 3: Reverification and rehires

Section 3 is used when employment authorization needs to be updated. This typically applies when:

• An employee’s work authorization expires

• An employee is rehired within three years of the original form

In these cases, the employer must reverify authorization and update the form accordingly. Failing to track expiration dates can expose organizations to avoidable compliance risk.

What documents are acceptable for I-9 verification?

To complete Section 2, employees must present documentation that proves identity and work authorization. Federal guidelines group acceptable documents into three categories. Employees may choose which documents to provide, as long as they meet the requirements.

U.S. Citizenship and Immigration Services (USCIS) publishes a detailed list of acceptable Form I-9 documents in its official guidance.

List A: Documents that establish both identity and work authorization

Documents in List A satisfy both requirements on their own. If an employee presents a valid List A document, no additional documentation is needed.

Examples include:

• U.S. passport

• Permanent Resident Card (Green Card)

• Employment Authorization Document (EAD)

List B: Documents that establish identity only

List B documents confirm identity but do not establish work authorization. When an employee presents a List B document, they must also provide a valid List C document.

Examples include:

• Driver’s license

• State-issued ID

• School ID card with photograph (typically for individuals under the age of 18 or in limited circumstances outlined in the Form I-9 instructions)

List C: Work authorization only

List C documents confirm employment authorization but do not establish identity. These must be paired with a valid List B document.

Examples include:

• Unrestricted Social Security card (cards marked “NOT VALID FOR EMPLOYMENT” or similar restrictions are not acceptable)

• Birth certificate (issued by a US state, county, municipal authority, or territory and bearing an official seal).

• Certificate of U.S. citizenship or naturalization

Employers may not specify which documents an employee must present. Federal law prohibits “document abuse,” which includes requesting more or different documents than required or rejecting valid documents that appear genuine.

I-9 deadlines and retention requirements

Timing is one of the most common areas where employers make mistakes. Form I-9 has strict completion deadlines, and missing them even by a day can create compliance exposure.

• Section 1 must be completed by the employee no later than their first day of employment for pay.

• Section 2 must be completed by the employer within three business days of the employee’s first day of employment for pay.

And if employment lasts fewer than three business days, the entire form must be completed by the first day of work.

Failure to meet these deadlines can result in civil penalties. According to U.S. Immigration and Customs Enforcement (ICE), fines for I-9 paperwork violations can range from hundreds to thousands of dollars per form, depending on the severity and whether violations are repeated.

While not every error results in maximum penalties, incomplete or improperly timed forms are among the most frequently cited issues during worksite inspections. Civil penalty amounts are adjusted annually for inflation and are published in the Federal Register.

How long must employers retain Form I-9?

Completing the form is only part of the requirement. Employers must also retain it for a specific period of time.

Form I-9 must be kept for:

• Three years after the date of hire OR

• One year after employment ends

Whichever date is later.

This retention rule ensures the form is available if a government agency conducts an audit or inspection. Official retention guidance is available from USCIS.

Employers must also be able to present Forms I-9 within three business days after service of a Notice of Inspection (NOI) from the Department of Homeland Security, the Department of Justice, or the Department of Labor. That makes secure storage and organized retrieval just as important as accurate completion.

For HR teams managing multiple hires, structured document archiving solutions can help support retention timelines, maintain record integrity, and simplify retrieval if an audit occurs.

Electronic I-9 systems and digital workflows

Employers may complete and retain Form I-9 electronically, provided their system complies with federal regulations. Identity and work authorization documents must be examined by the employer or an authorized representative, either through physical examination or, where permitted, through authorized alternative procedures for qualified employers enrolled in E-Verify and in good standing. The completed form may be signed and stored electronically if regulatory standards are met.

Federal rules require, among other things, electronic I-9 systems to:

• Ensure the electronic signature is permanently affixed to the electronic record 

• Preserve secure audit trails

• Maintain records verifying the identity of the individual producing the signature

• Implement reasonable controls to ensure data integrity and accuracy

• Prevent unauthorized alteration or deletion of records

• Use indexing and storage systems that allow prompt retrieval during an inspection

• Support internal inspection and quality assurance processes

• Reproduce legible copies of records if requested during an audit

In practice, many HR teams incorporate tools that allow employees to add an electronic signature to PDF documents as part of their onboarding process. When implemented correctly, electronic signing can help streamline documentation while maintaining the integrity and traceability required by federal law.

For HR teams managing hiring at scale, digitizing portions of the onboarding process — such as securely capturing electronic signatures and centralizing records — can reduce administrative errors and improve deadline tracking. Electronic workflows do not remove compliance obligations. When implemented in accordance with federal electronic I-9 regulations, electronic signing can streamline documentation while preserving required audit trails and record integrity.

Common I-9 mistakes to avoid

Even small technical errors on Form I-9 can create compliance exposure. During inspections, agencies focus on whether forms were completed accurately, on time, and retained properly. Administrative oversights — not intent — are often what trigger penalties.

Some of the most common issues include:

• Missing or incomplete signatures

• Late completion of Section 2

• Accepting documents that are expired, restricted, or otherwise not on the Lists of Acceptable Documents

• Failing to reverify expiring work authorization

• Inconsistent storage or recordkeeping practices

While agencies may distinguish between technical and substantive violations, repeated errors can increase penalty exposure and scrutiny.

Employers are responsible for maintaining accurate hiring documentation and complying with federal labor and employment requirements. The U.S. Department of Labor provides additional guidance in its hiring and employment resources.

Conducting periodic internal reviews helps identify issues before an inspection occurs. For organizations managing hiring across departments or locations, structured processes supported by compliance management tools can improve deadline tracking, document oversight, and reporting consistency.

Proactive monitoring reduces last-minute remediation efforts and supports more defensible compliance practices. Even minor errors can create compliance risk during an audit.

General employer compliance guidance is available from the U.S. Department of Labor.

Take the stress out of employment eligibility compliance

Form I-9 plays a central role in employment eligibility verification. Understanding what the form is used for, how it must be completed, and how long it must be retained helps reduce compliance risk and avoid preventable penalties.

While the process may seem straightforward, timing requirements, document verification rules, and retention standards leave little room for error. Even minor administrative mistakes can create exposure during an inspection.

As hiring needs grow and teams become more distributed, many organizations look for ways to make onboarding documentation more consistent and easier to manage. Secure electronic workflows and structured recordkeeping processes can help support compliance while reducing manual effort.

Clear policies, accurate documentation, and proactive oversight remain the foundation of effective I-9 management.

Frequently asked questions about Form I-9

What is the purpose of Form I-9?

The purpose of Form I-9 is to verify an employee’s identity and authorization to work in the United States.

Who needs to complete an I-9 form?

Every employee hired to work in the U.S. must complete one, regardless of citizenship or immigration status. Independent contractors generally do not complete Form I-9.

When must the I-9 form be completed?

Section 1 must be completed by the employee no later than the first day of employment for pay. Section 2 must be completed within three business days of the employee’s first day of employment.

How long must employers keep I-9 forms?

Employers must retain Form I-9 for three years after hire or one year after employment ends, whichever is later.

What happens if an I-9 form is not completed?

Employers may face civil fines and penalties following a government audit or inspection.

Can I-9 forms be completed electronically?

Yes, if the electronic system meets federal security, audit, and retention requirements.