Verified against official sources — 31 Oct 2026

Starting Work on H-1B: I-9, Payroll, Your I-94 and the First Month, Step by Step

NEW Published 31 October 2026

Illustration of a new employee at an office desk completing first-day paperwork beside a laptop, in navy and gold

The petition is approved and your start date is set — here is the paperwork that fills your first days: Form I-9, Form W-4, your Social Security number, and the taxes on your first payslip.

An H-1B approval is the end of a long process — and the start of a shorter, very practical one. In your first days you will attest to your work authorisation on Form I-9, show your documents for your employer's check, hand in a Form W-4 so the right tax comes out of your pay, and discover that Social Security and Medicare taxes apply to H-1B wages even if they never applied to you as a student. None of this is difficult, but two deadlines are measured in days, not weeks: your part of Form I-9 is due no later than your first day of work, and your employer's document check follows within three business days. This guide walks through the first month in the order the paperwork arrives. It covers starting with the employer who petitioned for you; changing employers, registration and the cap-gap are separate topics, covered by the guides linked below. Items are labelled RULE (an official requirement) or ADVICE (a preparation tip).

Quick answer

On or before your first day of work, complete Section 1 of Form I-9 — your employer must then examine your original, unexpired documents and complete Section 2 within three business days. Give your employer a completed Form W-4 so federal income tax is withheld correctly; if you never hand one in, you are treated as a single filer with no other adjustments. A Social Security number is not a condition of starting: if you have applied and it has not arrived, the I-9 instructions say you may begin working while you wait, as long as you can present your I-9 documents. From the first payslip, expect federal income tax plus Social Security and Medicare taxes — the IRS's exemption list does not include H-1B. And after any entry to the U.S., pull up your electronic I-94 and check its Admit Until date.

SECTION 01Before Day One: What Your Employer Has Already Done

RULE — Your H-1B rests on your employer's petition, in three steps. U.S. Citizenship and Immigration Services (USCIS) describes the sequence: the employer obtains a certified Labor Condition Application (LCA) from the Department of Labor (DOL); the employer files Form I-129, the petition for a nonimmigrant worker, with USCIS, including the certified LCA; then, if approved and you are outside the United States, you apply for the visa and for admission. Your authorisation is tied to that employer's petition — not a general permit to work for anyone.

RULE — Admission is generally for up to three years. USCIS states that an H-1B worker may generally be admitted for a period of up to three years. The dates that will govern your first month are the ones on your approval notice and — after any entry from abroad — the Admit Until date on your I-94 (Section 07), not the dates in an offer letter.

ADVICE — Keep the approval paperwork together. Your approval notice, passport and I-94 record (Section 07) are what the first month keeps asking for — one folder, paper or scanned, saves repeated searches.

SECTION 02Day One: Form I-9, Section 1 — Your Attestation

RULE — Every new hire completes Form I-9, citizens and non-citizens alike. Federal law requires every U.S. employer to complete Form I-9, Employment Eligibility Verification, for each person hired. The form verifies identity and employment authorisation: you complete Section 1; your employer completes Section 2 after examining your documents.

RULE — Section 1 is due no later than your first day of employment. The Form I-9 instructions state it directly: employees must complete and sign Section 1 no later than the first day of employment — the day you begin performing labour or services in return for wages. You may complete it earlier, but not before you have accepted an offer of employment.

RULE — As an H-1B worker you attest as "an alien authorized to work." Section 1 asks you to select one status box; the fourth — an alien authorized to work — is the one that fits. You then enter the date your employment authorisation expires, and one of: your USCIS Number (A-Number), your Form I-94 admission number, or your foreign passport number with its country of issuance. Enter every detail exactly as your documents show it — and, the instructions add for the dates in this part of the form, do not backdate them.

RULE — The Social Security number field has its own rule. Providing your nine-digit Social Security number in Section 1 is voluntary, unless your employer participates in E-Verify, in which case you must provide it (Section 04 covers what happens if it has not arrived yet). One trap the instructions name explicitly: do not enter an Individual Taxpayer Identification Number (ITIN) in the Social Security number field — an ITIN is a tax number, not an SSN.

SECTION 03The Document Check: Section 2 and the Three-Business-Day Rule

RULE — Your employer examines your documents within three business days. Within three business days after your first day of employment, you must present original, acceptable, unexpired documentation establishing your identity and employment authorisation, and your employer must complete Section 2 recording it. USCIS's example: begin on a Monday, and the document check is due on or before the Thursday of that week. If you were hired to work for fewer than three business days, everything is due on the first day instead.

RULE — You choose the documents; your employer cannot choose for you. You present either one document from List A (which shows both identity and employment authorisation) or one each from List B (identity) and List C (employment authorisation) of the Lists of Acceptable Documents that come with the form. USCIS's anti-discrimination notice is unambiguous: employers cannot specify which acceptable documentation an employee presents, cannot ask for documents to verify what you wrote in Section 1, and if your documents reasonably appear genuine and related to you, your employer must accept them. The examination is normally physical; some employers instead use a DHS-authorised alternative procedure, which they must indicate on the form.

RULE — The form stays with your employer; it is not sent to the government. USCIS instructs employers not to file Form I-9 with USCIS or ICE. Your employer retains it — three years after the date of hire or one year after employment ends, whichever is later — for inspection by authorised officials.

ADVICE — Bring originals, on day one, not day three. Photocopies are not acceptable for the check (a certified copy of a birth certificate is the only copy exception). If a document is genuinely unavailable, tell your employer before the deadline, not after, and ask what the official instructions allow in that situation.

SECTION 04Your Social Security Number: Needed for Payroll, Not for Starting

RULE — You can start work while your SSN is on its way. The Form I-9 instructions address the new-arrival situation directly, in their E-Verify guidance: if you have applied for a Social Security number but not yet received it, leave the Section 1 field blank and update it — initialling and dating the change — once it arrives; and if you can present acceptable I-9 documents, you may begin working while waiting for the number.

How to get the number itself is a guide of its own. Who qualifies, which documents the Social Security Administration asks for, the waiting period after entry, and how long the card takes are covered step by step in our Social Security number guide, linked below — this guide deliberately does not repeat it. The first-month point is only this: an SSN application in progress does not delay your start date, but payroll needs the number once it arrives, so hand it over as soon as you have it.

SECTION 05Form W-4: Setting Your Federal Withholding

RULE — Form W-4 tells your employer how much federal income tax to hold back. The Internal Revenue Service (IRS) describes the form's purpose plainly: complete Form W-4 so that your employer can withhold the correct federal income tax from your pay. Federal income tax is pay-as-you-go — your employer withholds it from each paycheck and pays it to the IRS in your name, rather than you settling the whole year at filing time.

RULE — Only two steps of the W-4 are required of everyone. Step 1 (your personal information and filing status) and Step 5 (your signature). Steps 2–4 apply only if they fit your situation — a second job, a working spouse, dependents, other income or deductions — and completing them is what makes the withholding match your actual liability.

RULE — No W-4 means withholding on default settings. New employees who fail to furnish a Form W-4 are treated as a single filer with no other adjustments: withholding is worked out on that single-filer basis alone, with nothing else about your situation taken into account. For many new arrivals that over- or under-withholds — hand the form in during your first days rather than discover the default on your first payslip.

RULE — Which W-4 instructions apply to you depends on your tax residency, not your visa label. The IRS treats resident aliens the same as U.S. citizens for income tax withholding. Nonresident aliens follow special W-4 rules instead, in the IRS's Notice 1392 — among other things, a nonresident alien checks "Single or Married filing separately" in Step 1(c) regardless of actual marital status and cannot write "exempt" on the form.

ADVICE — If you don't know your category, ask payroll before you complete the form — the two rule sets produce different withholding, and tax residency is not decided by your visa label alone.

SECTION 06Social Security and Medicare Taxes: Yes, They Apply to H-1B

RULE — Wages for work in the U.S. are generally subject to Social Security and Medicare taxes. The IRS states the general rule for nonresident aliens employed in the United States by an American or foreign employer: their wages are, in general, subject to Social Security and Medicare taxes for services performed in the United States, with certain exceptions based on nonimmigrant status. For resident aliens, the same taxes apply under the same rules as for U.S. citizens.

RULE — The exemption list does not include H-1B. The IRS lists the exempt classes of nonimmigrants: among them A-visa government employees, certain D-visa crew members, G-visa international-organisation employees, certain H-2 and H-2A workers — and F, J, M and Q visa holders. H-1B appears nowhere in the list; the only H-visa exemptions named are the narrow H-2 and H-2A cases. The general rule therefore reaches your payslip: both taxes are withheld from H-1B wages from the first paycheck.

RULE — The student exemption does not follow you into H-1B. If you arrived at H-1B from F-1 status, this is the change that surprises people. The F-visa exemption belongs to nonresident aliens in F-1, J-1, M-1 or Q-1 status, and the IRS lists its limits: it does not apply to nonimmigrants in those statuses who change to a status which is not exempt, and it does not apply once such a person becomes a resident alien for tax purposes. A change of status to H-1B ends the exemption on both counts — expect Social Security and Medicare lines on your payslip even if your student payslips never had them. (A totalization agreement between the U.S. and your country can occasionally alter the position; the IRS notes such agreements exist, and your payroll team can confirm whether one covers you.)

SECTION 07Check Your I-94: The Date That Governs Your Stay

RULE — Your arrival record is electronic, and you can read it. U.S. Customs and Border Protection (CBP) gathers arrival and departure information automatically from electronic travel records; travellers who need to prove their legal-visitor status — to employers, among others — can access their record online. On the CBP I-94 website (or the CBP GO app), "Get Most Recent I-94" produces your current record, which you can print yourself.

ADVICE — Check the Admit Until date every time you enter. The I-94 website displays your admission record and its Admit Until date — the date by which you must depart or extend. After each entry, pull the record up and compare that date with your petition approval: a shorter I-94 — often because a passport expires sooner — shortens your authorised stay regardless of the approval notice. Keep a copy with your approval paperwork. Why the visa stamp, your status and the I-94 are three different things, and how an incorrect I-94 gets fixed, is a full topic of its own, covered in our visa vs status vs I-94 guide linked below; the first-month version is simply: look early, while a correction is still easy.

SECTION 08The Employer's Promises: The LCA Behind Your Job

RULE — Before petitioning, your employer made four attestations to the Department of Labor. USCIS summarises the LCA your employer had certified: the employer attests that it will pay the H-1B worker a wage no less than the wage paid to similarly qualified workers or, if greater, the prevailing wage for the position in the area of employment; that it will provide working conditions that do not adversely affect similarly employed workers; that there is no strike or lockout at the place of employment; and that notice of the LCA filing was given to the workers' bargaining representative or posted at the place of employment.

ADVICE — The posted notice and your payslip should tell the same story. The notice posted at your workplace (or given to the union representative) is how most H-1B workers first see that an LCA covers their role, and the wage attestation is its core promise: the LCA rate for your position is a floor for your pay, not a target. Ask your employer for a copy of the certified LCA and keep it with your approval notice. If your actual pay falls below that rate, raise it with your employer in writing promptly — that gap is exactly what the attestation exists to prevent. The LCA and its posting are the employer's duties, not yours; your part is to know they exist and keep the evidence.

SECTION 09The Rest of the First Month: Keeping the File Straight

RULE — When your authorisation is extended, the I-9 is revisited. Form I-9 reverification — recorded on Supplement B — is required by the earlier of the employment-authorisation expiration date you entered in Section 1 or the expiration date of the employment-authorisation document recorded in Section 2. An approved H-1B extension is the usual trigger in your first years: expect your employer to ask you to present a document showing continuing authorisation, and to choose which acceptable document to present, as you did the first time.

RULE — Your wages are reported on Form W-2. Every employer must complete and file Form W-2, Wage and Tax Statement, for each employee from whom income, Social Security or Medicare tax was withheld. The W-2 issued after the year ends is what your first U.S. tax return is built from — and the first place to check that your name and Social Security number are recorded exactly right.

ADVICE — Three habits that make month two easier. (1) Give payroll your SSN the day it arrives, and check it character-by-character on your next payslip. (2) Keep every payslip: quiet evidence of the LCA wage being paid and of your employment dates. (3) If you move home, a separate address-reporting duty applies to most non-citizens — our change-of-address guide covers the AR-11 rule and its deadline; your first month is the wrong time to discover it late.

FAQFrequently Asked Questions

Can I start work before my Social Security number arrives?

Yes. The Form I-9 instructions say that if you have applied for an SSN but not yet received it, you leave the Section 1 field blank (if your employer uses E-Verify) and update it when the number arrives — and that if you can present acceptable I-9 documents, you may begin working while you wait. Payroll needs the number once issued, so hand it over promptly.

My employer asked for my passport specifically for Form I-9. Is that allowed?

No. USCIS's anti-discrimination notice states that employers cannot specify which acceptable documentation an employee presents, and cannot ask for documents to verify the information entered in Section 1. You choose: one List A document, or one List B plus one List C document, from the official Lists of Acceptable Documents. If your chosen documents reasonably appear genuine and relate to you, your employer must accept them.

What happens if I never hand in a Form W-4?

Your employer still withholds — on default settings. The IRS states that new employees who fail to furnish a Form W-4 are treated as a single filer with no other adjustments: withholding is calculated on that basis alone, ignoring dependents, other income and deductions. A completed W-4 (only Steps 1 and 5 are required of everyone) makes the withholding fit your situation.

I paid no Social Security tax as an F-1 student. Why is it on my H-1B payslip?

Because the exemption belonged to your old status, not to you. The IRS exempts nonresident aliens in F-1, J-1, M-1 and Q-1 status from Social Security and Medicare taxes on authorised services — and states that the exemption does not apply to people in those statuses who change to a status which is not exempt, or who become resident aliens. H-1B is not among the IRS's exempt classes, so the general rule applies: both taxes are withheld from H-1B wages.

Where do I check how long I have been admitted for?

On CBP's I-94 website, using "Get Most Recent I-94": your electronic arrival record shows the Admit Until date for this entry, and you can print it from the site. Check it after every entry — the Admit Until date, not the visa stamp, is the date your authorised stay ends.

Editorial note: This AllVisaUpdates guide is general educational information about the standard first-month employment paperwork for H-1B workers. It is not legal or tax advice — Form I-9 is completed with your employer, withholding questions go to your payroll team or a tax professional, and status questions to your employer's immigration counsel. Items labelled RULE come from the official sources below, checked on 31 October 2026; items labelled ADVICE are preparation recommendations.

Official references and verification status

These official references were accessed and checked on 31 October 2026, and this guide's RULE items were verified claim-by-claim against them (record in the accompanying .sources.md file). Two sourcing notes. First, the Department of Labor's own H-1B pages could not be read in this pass (dol.gov returned an access error), so Section 08 rests on USCIS's own published summary of the Labor Condition Application attestations, and no DOL-specific procedure beyond them is asserted. Second, the I-9 deadline wording is taken from the official Instructions for Form I-9 (USCIS, edition 01/20/25); the Handbook for Employers (M-274) landing page rendered no guidance text in this pass.

General educational information, not individualized legal or tax advice. Consult your employer's immigration counsel or a qualified tax professional for case-specific questions.

General information only. This guide is based on official sources publicly available and checked on the date shown on this page. Visa rules change, and consular and USCIS officers decide every case on its own facts — nothing here is a confirmation or a guarantee for your individual case, and this is not legal advice. Always confirm the current requirement on the official page linked in this guide before you act, and consider a qualified immigration attorney for your specific situation.