Yes, Mexicans pay U.S. taxes whenever they earn income from a U.S. source or spend enough time in the country to be classified as a U.S. tax resident. The IRS does not care about citizenship or immigration status when it decides who owes federal income tax. It cares about two things: where the income comes from, and how the taxpayer’s residency is classified under U.S. tax rules. Wages from U.S. work are taxed at the same graduated rates that apply to U.S. citizens, from 10% up to 37%. Passive income like dividends and interest is taxed at a flat 30%, though the U.S.-Mexico tax treaty often cuts that rate substantially.
Who Counts as a U.S. Tax Resident
The classification matters because resident aliens owe U.S. tax on their worldwide income, while nonresident aliens owe tax only on income from U.S. sources. The IRS uses two tests.
The Green Card Test
Any Mexican national who holds a lawful permanent resident card at any point during the calendar year is treated as a resident alien for the entire tax year. All income for that year, wherever it was earned, is subject to U.S. federal income tax.1Internal Revenue Service. U.S. Tax Residency – Green Card Test
The Substantial Presence Test
Someone without a green card can still be a resident alien by spending enough time in the U.S. The IRS counts all days present in the current year, one-third of the days from the prior year, and one-sixth of the days from two years back. If the total reaches 183, and the person was present at least 31 days in the current year, they are a resident alien for tax purposes.2Office of the Law Revision Counsel. 26 USC 7701 – Definitions
The Border Commuter Exception
Mexican nationals who live in Mexico and commute across the border to work each day get an important break. Commuting days do not count toward the substantial presence test.3Internal Revenue Service. Substantial Presence Test A daily commuter to El Paso or San Diego may never accumulate enough days to be treated as a resident. That worker still owes U.S. tax on wages earned in the U.S., but only as a nonresident, with no obligation to report income earned in Mexico.4Office of the Law Revision Counsel. 26 USC 7701 – Definitions
The Closer Connection Exception
Even a person who meets the substantial presence test can stay a nonresident by filing Form 8840 and showing a closer connection to Mexico. The taxpayer must have been in the U.S. fewer than 183 days that year, kept a tax home in Mexico all year, and shown stronger ties to Mexico through a permanent home, family, belongings, and social or business connections. Anyone who has applied for a green card cannot use this exception.5Internal Revenue Service. Closer Connection Exception to the Substantial Presence Test
Immigration Status Is Not the Trigger
A widely held belief is that undocumented workers do not pay U.S. taxes. The IRS does not consider immigration status when determining who owes. Anyone earning U.S.-source income is expected to file and pay, whether they hold a visa, a green card, or nothing at all. Employers routinely withhold federal income tax, Social Security, and Medicare from paychecks regardless of the worker’s status. Filing a return does not expose immigration status: the IRS is generally prohibited from sharing taxpayer information with other agencies.
To make compliance possible for people who cannot get a Social Security Number, the IRS issues the Individual Taxpayer Identification Number. Applying requires Form W-7, a tax return, and proof of identity and foreign status, usually a valid passport.6Internal Revenue Service. How to Apply for an ITIN Processing runs about seven weeks normally and nine to eleven during tax season.7Internal Revenue Service. Individual Taxpayer Identification Number (ITIN) Certified Acceptance Agents can verify documents in person so the applicant does not have to mail an original passport.
An ITIN does not authorize work, change immigration status, or create eligibility for Social Security benefits. It exists for tax administration. Any ITIN that goes three consecutive years without appearing on a return expires on December 31 of that third year and must be renewed.8Internal Revenue Service. How to Renew an ITIN
What Income Gets Taxed, and How
The rate depends on the type of income and the taxpayer’s residency status.
Wages and Self-Employment (Effectively Connected Income)
Wages, salaries, commissions, and self-employment earnings from work done in the U.S. are taxed at the same graduated rates that apply to citizens: 10% on the first $12,400 of taxable income up to 37% on income above $640,600 for a single filer in 2026.9Internal Revenue Service. IRS Releases Tax Inflation Adjustments for Tax Year 2026 Employers withhold federal income tax. Business expenses tied to producing this income are generally deductible.
Passive Income (FDAP)
Dividends, interest, royalties, and rental income from U.S. sources that are not connected to a trade or business are taxed at a flat 30%. The payer, whether a bank, brokerage, or tenant, usually withholds the tax before paying.10Internal Revenue Service. Fixed, Determinable, Annual, or Periodical (FDAP) Income No deductions are allowed against this category. The U.S.-Mexico treaty often reduces the 30% rate.
U.S. Real Estate Sales
When a Mexican national who is a nonresident sells U.S. real property, the buyer must generally withhold 15% of the total sale price and remit it to the IRS under the Foreign Investment in Real Property Tax Act. The withholding is a prepayment of any capital gains tax owed. The seller files a return to report the actual gain and can claim a refund if the withholding exceeds the tax due.11Internal Revenue Service. FIRPTA Withholding
How the U.S.-Mexico Tax Treaty Cuts the Bill
The bilateral treaty between the two countries is designed to keep the same income from being taxed twice. A Mexican resident who qualifies under the treaty can claim several benefits.12Internal Revenue Service. United States – Mexico Income Tax Convention
Lower Rates on Passive Income
- Dividends: 5% if the recipient is a company owning at least 10% of the paying company’s voting stock; 10% otherwise.13U.S. Department of the Treasury. Second Protocol to U.S.-Mexico Income Tax Convention, November 2002
- Interest: from 4.9% on bank loans and publicly traded bonds up to 10% on certain other bank-paid interest and seller-financed equipment purchases, and 15% in all other cases.12Internal Revenue Service. United States – Mexico Income Tax Convention
Short-Term Work Exemption
A Mexican resident who comes to the U.S. temporarily for work may be exempt from U.S. tax on those earnings if present for no more than 183 days in a 12-month period, paid by a Mexican employer, and the compensation is not charged to a U.S. business location. The exemption applies separately to employment income and to independent services like consulting.12Internal Revenue Service. United States – Mexico Income Tax Convention
Student and Trainee Exemption
Payments a Mexican student or trainee receives for education or training, such as scholarships or maintenance payments, are not taxed in the U.S. as long as they come from sources outside the country. The treaty sets no dollar cap or time limit on this exemption.12Internal Revenue Service. United States – Mexico Income Tax Convention
Claiming the Benefits
Treaty positions must be disclosed on Form 8833, filed with the return. A separate form is required for each provision claimed, and failing to disclose can trigger a penalty even when the benefit itself would have been allowed.14Internal Revenue Service. Form 8833 Treaty-Based Return Position Disclosure
Social Security and Medicare
Mexican nationals working in the U.S. generally pay Social Security tax at 6.2% and Medicare tax at 1.45%, with employers matching. Two exceptions can eliminate these taxes.
The U.S.-Mexico totalization agreement prevents double coverage. A Mexican worker temporarily assigned to the U.S. by a Mexican employer can get a Certificate of Coverage from Mexico’s social security agency, which exempts both the worker and the employer from U.S. Social Security and Medicare taxes. Without the certificate, both countries could tax the same wages.15Social Security Administration. Totalization Agreements
Mexican agricultural workers admitted on H-2A visas are fully exempt from U.S. Social Security and Medicare taxes. The exemption comes from the visa itself and applies whether the worker is a resident or nonresident alien. Employers should not report Social Security or Medicare wages on the H-2A worker’s W-2.16Internal Revenue Service. Foreign Agricultural Workers on H-2A Visas
Credits and Deductions
Not every benefit available to citizens is available to Mexican filers. The tax identification number the filer uses is often decisive.
- Earned Income Tax Credit. Requires a valid Social Security Number for the taxpayer, spouse, and each qualifying child. ITIN holders are not eligible. The one exception is a nonresident alien who files jointly with a U.S. citizen or resident spouse and elects to be treated as a resident.17Internal Revenue Service. Who Qualifies for the Earned Income Tax Credit (EITC)
- Child Tax Credit. Both the taxpayer (or at least one spouse on a joint return) and each qualifying child must have a Social Security Number valid for employment, issued before the return’s due date. Children with ITINs do not qualify, though a dependent with an ITIN may qualify for the smaller Credit for Other Dependents.18Internal Revenue Service. Child Tax Credit
- Standard deduction. Nonresident aliens filing Form 1040-NR generally cannot use the standard deduction and are limited to itemized deductions tied to their U.S. income. Resident aliens get the same standard deduction as U.S. citizens.19Internal Revenue Service. Nonresident – Figuring Your Tax
One benefit worth flagging: a nonresident who is a resident of Mexico and whose spouse died within the past two years may file as a qualifying surviving spouse and use the joint return tax rates, provided they have a dependent child living with them.19Internal Revenue Service. Nonresident – Figuring Your Tax
Reporting Mexican Bank Accounts and Assets
Once a Mexican national is treated as a U.S. tax resident, accounts and investments back in Mexico may trigger reporting obligations.
The FBAR, filed as FinCEN Form 114, is required from anyone with a financial interest in or signature authority over foreign financial accounts whose combined value exceeded $10,000 at any point in the year.20Financial Crimes Enforcement Network. Report Foreign Bank and Financial Accounts It is filed electronically through the BSA E-Filing System, not with the tax return. Penalties for failing to file can be significant, and they are steeper for willful violations.21Federal Register. Inflation Adjustment of Civil Monetary Penalties
Form 8938, under FATCA, is a separate filing that goes with the tax return. Resident aliens living in the U.S. must file it if their foreign financial assets exceed $50,000 on the last day of the year or $75,000 at any point during the year. The thresholds double for married couples filing jointly and are much higher for taxpayers living abroad — $200,000 at year-end or $300,000 during the year for an individual filer.22Internal Revenue Service. Do I Need to File Form 8938, Statement of Specified Foreign Financial Assets The FBAR and Form 8938 have different thresholds and filing methods; anyone who meets both must file both.
Which Form to File and When
Resident aliens file Form 1040, the same return citizens use. Nonresident aliens file Form 1040-NR.23Internal Revenue Service. Taxation of Nonresident Aliens A nonresident has to file if they are engaged in a U.S. trade or business, if they have U.S. income on which the full tax was not withheld at the source, or if they want a refund of over-withheld tax.24Internal Revenue Service. Nonresident Aliens
The standard deadline is April 15 for nonresidents who receive wages subject to U.S. withholding or have a U.S. office. Nonresidents who do not receive wages subject to withholding and have no U.S. office get an automatic extension to June 15.23Internal Revenue Service. Taxation of Nonresident Aliens Resident aliens living outside the country also get the automatic two-month extension to June 15.25Internal Revenue Service. Get an Extension to File Your Tax Return Form 4868 pushes the filing deadline to October 15, but any tax owed is still due by the original April date.
Filing late costs 5% of the unpaid tax for each month or partial month the return is overdue, up to 25%.26Internal Revenue Service. Failure to File Penalty A separate 0.5% monthly penalty applies for late payment. When both apply in the same month, the filing penalty is reduced by the payment penalty, keeping the combined rate at 5%.27Internal Revenue Service. Failure to Pay Penalty Payments can go through the Electronic Federal Tax Payment System, by direct debit, or by check with the return. Anyone who cannot pay in full may request an installment agreement. Keep copies of every filing; Mexican nationals often need proof of tax compliance for immigration applications and financial matters later on.