Americans in Mexico: What Your US Tax Return Looks Like Now

More than a million Americans now call Mexico home, drawn by the cost of living, the climate, and a shorter flight back to see family. What doesn’t change when the moving truck pulls away is the US tax return.

A Treaty With Limits

The US-Mexico tax treaty prevents some forms of double taxation, but it does not exempt Americans from filing. Every US citizen and green card holder must report worldwide income to the IRS regardless of where they live. The treaty mainly resolves conflicts over which country taxes specific categories of income first, and it leans on a set of tiebreaker rules when both countries could otherwise claim someone as a resident.

Most people assume a treaty means they are covered. In practice, the treaty is a tiebreaker, not an exemption, and it rarely eliminates a filing requirement on either side of the border.

Mexican Residency Status Matters Too

Mexico determines its own tax residency separately from anything the IRS decides. Spending more than 183 days in Mexico in a calendar year, or establishing a “center of vital interests” there, generally makes someone a Mexican tax resident on worldwide income. That status exists independently of US citizenship and independently of the Physical Presence Test used for the Foreign Earned Income Exclusion.

This is where a lot of Americans get their planning backward. They focus entirely on the US side of the calendar, the 330-day rule for FEIE, without realizing Mexico is running its own residency clock on a different set of facts.

FEIE and the Foreign Tax Credit

The Foreign Earned Income Exclusion lets qualifying expats exclude a set amount of foreign wages from US tax each year, provided they meet either the Physical Presence Test or the bona fide residence test. The Foreign Tax Credit works differently: it credits US tax liability for income taxes already paid to Mexico. Which one saves more money depends on income level, Mexican tax rates on that specific income, and whether the income even qualifies as “earned.”

Many Americans in Mexico use a combination of both, applying the exclusion to wages and the credit to other income types such as rental income or investment gains that FEIE was never designed to cover. Filing Form 2555 or claiming the credit incorrectly is one of the more common ways expats overpay, particularly when a preparer applies one method across every category of income without checking whether it actually qualifies.

Self-Employment Taxes Don’t Bend

Americans running a business or freelancing while living in Mexico often assume the exclusion covers everything, including self-employment tax. It doesn’t. FEIE reduces income tax, not the 15.3 percent self-employment tax that funds Social Security and Medicare, and that tax applies at the full US rate regardless of where the work is performed or how little income tax ends up being owed.

A US-Mexico totalization agreement exists to prevent paying into both countries’ social security systems on the same income, but it has specific conditions that have to be met, not an automatic exemption. Ignoring this piece is one of the more expensive mistakes self-employed expats make in Mexico.

The Reporting Nobody Mentions

Opening a Mexican bank account, a CETES investment account, or an AFORE retirement account creates a US reporting obligation, separate from income tax entirely. FBAR (FinCEN Form 114) is required once foreign accounts exceed $10,000 in aggregate at any point in the year, even if the balance sat above that threshold for a single day. Form 8938 has its own, higher thresholds and gets filed with the tax return itself rather than separately with the Treasury.

These forms do not calculate tax. They exist purely to disclose. Missing them carries penalties that are unrelated to whether any tax was actually owed, which means a fully compliant taxpayer with no unpaid tax can still face significant penalties for an unfiled FBAR.

Property Adds Its Own Layer

Buying property in Mexico, particularly through the fideicomiso structure required for foreign ownership near the coast, can create additional US filing requirements depending on how the arrangement is structured. Some fideicomiso arrangements have historically raised questions about foreign trust reporting, an area where the guidance has shifted over time. This is worth confirming before the purchase, not after.

Rental income from Mexican property, whether occupied part-time or rented out full-time, is also reportable on the US return regardless of whether any tax is owed to Mexico on the same income.

Two Systems, One Return

Because Mexico taxes residents on worldwide income as well, US citizens living in Mexico long-term navigate two unique sets of tax regulations on their income. Thankfully, tax treaties and foreign tax credit systems are designed to help prevent double taxation. Navigating these requirements effectively ensures full compliance while optimizing your overall tax position.

With experience serving clients in over 80 countries, the team at Smith Patrick is ready to help make your move to Mexico as smooth and tax-efficient as possible. Contact Smith Patrick today to schedule a consultation and ensure your US tax filings are handled with expertise and care.