Form I-9 vs W-4: A Simple Guide

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Form I-9 vs W-4: A Simple Guide - Side by Side Comparison

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Do you know that new employees in the United States compare Form I-9 vs W-4? These documents are similar when managing employee records but serve distinct purposes and are helpful at different employment stages.

These forms play a crucial role in hiring and employing individuals in the United States while ensuring compliance with various federal regulations.

Are you an employee looking to understand employment eligibility obligations or an employer seeking to ensure legal compliance by learning the Form I-9 vs W-4 difference? This article discusses everything beginners should know about these forms. Let’s get started.

What is Form I-9?

Form I-9 is a document for employers to verify employment authorization. It also validates the identity of individuals hired in the United States.

What is an i9 tax form is a common question among beginners and many don’t know where to submit it. However, it’s usually required by the Citizenship and Immigration Services in the United States, a part of the Homeland Security Department.

Employers must use Form I-9 under the Immigration and Reform Control Act when confirming an employee’s eligibility to work in the country after setting up a business. It includes reviewing certain legal documents, such as a green card or birth certificate, Social Security card, and driver’s license to establish identity.

What is Form W-4?

Form W-4, officially called the Employee’s Withholding Certificate, is a document for federal income tax withholding purposes in the United States.

Employees complete this form and submit it to employers. It determines the income tax business owners can withhold from the worker’s paycheck.

Form W-4 is essential for employers and employees to ensure the correct amount of federal income tax based on the worker’s personal and financial circumstances.

The IRS requires every employee to fill out this form, which includes information on the number of dependents and marital status.

Form I-9 vs W-4: When to Complete?

The differences between i9 and w4 varies for employers and employees in the United States. Let’s discuss when to complete them below:

When to Complete Form I-9

The Form I-9 is a three-part document. Employees must fill out the first section on the first day of work. The worker must provide personal information, such as full name, date of birth, address, immigration status, or citizenship, while signing and dating the form to prove employment eligibility.

The employer must fill out Section 2 within three business days from the employment date. The hiring manager examines the employee’s documents to establish identity and work eligibility.

It’s advisable to check and review the documents against the “List of Acceptable Documents” to ensure they match the information in the first section. Form I-9 IRS third section is usable when updating and re-verifying employees’ work authorization becomes necessary.

When to Complete Form W-4?

New workers must complete a Form W-4 on or before the resumption date. It helps determine how much federal income tax employers should withhold from their paychecks. The new hire should sign the Form W-4 before submission as it is invalid and incomplete without it.

Corporate or limited liability company Employers should process the completed Form W-4 at the beginning of the first payroll period until the 30th day from the receiving date.

For example, if a worker submits the Form W-4 on July 1st, the employer must process it by the start of the first payroll period ending on or after July 30th.

Form I-9 vs Form W-4: Understand the Difference?

Form I-9 and W-4 are vital documents used for tax and employment purposes in the United States, but they collect different information. Below are the key differences:

Form I-9: Employment Eligibility Verification

  •         Purpose: Employers verify employees’ employment eligibility and identity with the Form I-9. It includes U.S. and non-U.S. citizens.
  •         Information Collected: This form collects information on work authorization and identity of employees.
  •         Form I-9 has sections where applicants provide personal information, immigration status, citizenship, authorization to work in the U.S., and present documents describing their identity. Social Security cards, driver’s licenses, and passports are commonly accepted papers.
  •         Updates: You don’t need to regularly update Form I-9 for existing employees until there is a need for re-verification or the documentation for their work authorization expires.
  •         Retain Records: Employers should retain Form I-9 taxes documentation and records of every employee associated with the organization for a specified period.

Form W-4: Employee’s Withholding Certificate

  •         Purpose: Employees inform employers of the federal income tax amounts to withhold from their paychecks with the Form W-4.
  •         Information Collected: This form collects information about an employee’s tax withholding preferences, such as additional amounts to have withheld and the number of allowances to claim.
  •         Updates: Employees should update the Form W-4 when the tax situation changes. For example, it becomes necessary when you experience significant changes in income, get married, or have children.
  •         Retain Records: Employers must keep a copy of Form W-4 for every employee associated with the organization for a certain period. It ensures accurate tax withholding.

Employers and employees should educate themselves about these documents and work with experienced professionals to succeed.

Finally, entrepreneurs seeking a successful company registration without time-wasting or legal complexities should contact BusinessAnywhere Company Formation Service today. We’ll get you started and kickstart your business in record time. so contact us today to get your i9 vs 1099 or W-4 forms started.

Form I-9 vs W-4: Wrapping Up

Understanding the difference between Form I-9 vs W-4 is crucial for employers and employees in the United States. Although they may appear similar, they serve vastly different purposes, especially for taxation and employment.

Form I-9 serves as a verification tool for employers to check employees’ eligibility to work legally in the U.S. and verify identities, ensuring compliance with immigration laws. New workers declare their tax withholding preferences with the Form W-4.

Working with experienced professionals and following the appropriate guidelines to fulfill all obligations under U.S. labor and tax laws is advisable.

About Author

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Rick Mak

Rick Mak is a global entrepreneur and business strategist with over 30 years of hands-on experience in international business, finance, and company formation. Since 2001, he has helped register tens of thousands of LLCs and corporations across all 50 U.S. states for founders, digital nomads, and remote entrepreneurs. He holds degrees in International Business, Finance, and Economics, and master’s degrees in both Entrepreneurship and International Law. Rick has personally started, bought, or sold over a dozen companies and has spoken at hundreds of conferences worldwide on topics including offshore structuring, tax optimization, and asset protection. Rick’s work and insights have been featured in major media outlets such as Business Insider, Yahoo Finance, Street Insider, and Mirror Review.
“I’ve used many LLC formation services before, but this one is the best I’ve ever used—super simple and fast!” “Excellent service, quick turnaround, very professional—exactly what I needed as a non-US resident.”
You can read more feedback from thousands of satisfied entrepreneurs on the Business Anywhere testimonials page. As a contributor to Business Anywhere, Rick shares actionable guidance drawn from decades of cross-border business experience—helping entrepreneurs launch and scale legally, tax-efficiently, and with confidence. To learn more about how we ensure accuracy, transparency, and quality in our content, read our editorial guidelines.

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