Mexico-US Tax Treaty: What Americans Living in Mexico Need to Know

The US and Mexico have had a bilateral tax treaty in force since 1994. Most Americans living in Mexico have heard of it but misunderstand what it actually does. The treaty doesn’t exempt Americans from US taxes on Mexican income. What it does is provide mechanisms to avoid paying full taxes to both countries on the same income.

This guide breaks down the treaty’s key provisions, the saving clause that limits its benefits for US citizens, how foreign tax credits work in practice, and what Americans earning money while living in Mexico actually owe. For the broader picture on Mexico taxes for expats, start with that hub article first.

What the Treaty Covers

The US-Mexico Income Tax Treaty (formally the “Convention Between the United States of America and the United Mexican States for the Avoidance of Double Taxation and the Prevention of Fiscal Evasion”) covers:

• Residency tie-breakers — rules to determine which country has primary taxing rights when someone qualifies as a resident of both
• Business income — when profits of a US business are taxable in Mexico and vice versa
• Employment income — rules on where salary and wages are taxed
• Investment income — reduced withholding rates on dividends, interest, and royalties paid across the border
• Capital gains — rules on which country taxes asset sales
• Pensions and retirement — which country taxes Social Security and pension income
• Government employees — exemptions for government pay

The Saving Clause: Why the Treaty Doesn’t Exempt Americans

This is the most important thing Americans need to understand about the treaty. Article 1 contains a saving clause that reads essentially: the United States reserves the right to tax its citizens and residents as if the treaty did not exist.

In plain English: the US can still tax you on all your worldwide income, even if you’re a Mexican tax resident and even if Mexico has already taxed that income. The treaty does not override the US obligation to file and pay federal taxes as a US citizen. This is fundamentally different from how tax treaties work for nationals of most other countries — a French citizen who becomes a Mexican tax resident generally isn’t still liable to France. Americans are.

The saving clause has specific exceptions — certain treaty provisions still apply even for US citizens — but for most everyday income situations, if you’re a US citizen living in Mexico, you’re filing US federal taxes every year regardless of how long you’ve been gone.

Foreign Tax Credits: How Double Taxation Gets Avoided in Practice

The mechanism that prevents you from paying 35% to Mexico AND 37% to the US on the same income is the foreign tax credit (Form 1116). Here’s how it works:

If you earn $80,000 from freelance work while living in Mexico as a tax resident, Mexico might tax that income at roughly 20-25% (depending on deductions and whether you’re in RESICO). That Mexican tax paid can be claimed as a credit against your US federal tax on the same income. If you paid $16,000 to Mexico and your US federal liability on that income would be $18,000, you net $2,000 owed to the US — not both full amounts.

The credit is limited to the US tax rate — you can’t use excess foreign tax to create a US refund. And it requires careful accounting: you need documentation of Mexican taxes paid (your annual Mexican tax return and payment receipts) to claim the credit on your US return.

FEIE vs. Foreign Tax Credits: Which to Use

Americans in Mexico have two main tools for reducing US tax on foreign income: the Foreign Earned Income Exclusion (FEIE) and foreign tax credits. You generally can’t use both on the same income. The better choice depends on your situation:

For most Americans earning meaningful income while living in Mexico as a tax resident, foreign tax credits tend to be more beneficial than FEIE — particularly if Mexican tax rates are close to or higher than US rates on the same income bracket. Consult a cross-border CPA to model both scenarios for your specific income and filing situation.

Social Security and Pension Income

Under the treaty, US Social Security benefits paid to a Mexican resident are only taxable in the US — Mexico does not tax US Social Security. This is a direct treaty benefit that applies even given the saving clause. If you’re retiring to Mexico on Social Security, you won’t owe Mexican income tax on those payments.

US pension and IRA distributions are generally taxable only in the US under the treaty, with similar carve-outs. 401(k) withdrawals while in Mexico should be taxed only by the US.

FBAR and FATCA Still Apply

The treaty has no effect on reporting obligations. If you have Mexican bank accounts (or any foreign financial accounts) with aggregate balances exceeding $10,000 at any point during the year, you must file an FBAR (FinCEN 114) — separately from your tax return. FATCA Form 8938 filing thresholds are higher but also still apply. These are strict liability requirements with significant penalties for non-compliance.

Most Americans living in Mexico will have Mexican bank accounts — which is fine and normal, but means FBAR applies. The Mexico bank account service helps you get set up; keeping proper records for FBAR compliance is your responsibility as the account holder.

Canada-Mexico Treaty (For Canadian Readers)

Canada and Mexico also have a bilateral tax treaty (in force since 2006). Unlike the US treaty, it doesn’t include a broad saving clause. Canadians who properly sever Canadian tax residency before moving to Mexico can generally escape Canadian taxation on non-Canadian-source income. The challenge is “properly” — Canada’s departure rules are strict. See our guide on how to leave Canada for tax purposes for what’s required. Once done correctly, a Canadian living in Mexico as a Mexican tax resident owes Mexican ISR on worldwide income but not Canadian income tax on non-Canadian earnings.

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