Mexico — Tax Residency (Vital Interests Test)

Summary

Threshold

Vital interests (no day count)

Window

No statutory day rule

Also triggers

A permanent home in Mexico

Legal basis

CFF Art. 9

Authority

SAT

Mexico has no 183-day rule. You are a Mexican tax resident while you keep a permanent home (casa habitación) in Mexico — and, if you also keep a home abroad, while your centre of vital interests stays in Mexico. Day counts are supporting evidence only, not the test itself, so simply staying under 183 days does not end your residency.

Who it applies to

This matters most if you are:

• A remote worker or digital nomad who keeps an apartment or family home in Mexico while travelling.
• Someone earning most of their income from Mexican clients, employers, or businesses.
• A Mexican national living abroad who has not filed a formal change-of-residence notice with SAT.
• An expat moving out of Mexico who assumes leaving the country automatically ends tax residency.

The test applies to individuals regardless of nationality, but Mexican nationals carry an extra presumption of residency and a heavier burden to prove they have left.

The rule — and why it exists

Residency is defined by Article 9 of the Código Fiscal de la Federación (CFF), administered by the tax authority, SAT. It runs on your home and economic centre rather than a tally of days:

• Permanent home. If your only home (casa habitación) is in Mexico, you are a Mexican tax resident — day count is irrelevant.
• Centre of vital interests. If you also keep a home abroad, Mexico breaks the tie by asking where your economic and personal life is centred.

Why it exists: a home and an income base are stable proxies for where your economic life really sits. Tying residency to those factors — instead of a day threshold — stops people shedding residency simply by counting days while keeping their home and livelihood in the country.

Applying the test

Because there is no day count, the test runs in two steps: first your home, then — only if you have homes in more than one country — where your vital interests are centred.

1. 1Do you have a permanent home (casa habitación) in Mexico? If it is your only home, you are a Mexican tax resident and the test stops here.
2. 2If you also keep a home abroad, Mexico looks at your centre of vital interests to break the tie.
3. 3Your centre of vital interests is in Mexico if MORE THAN 50% of your yearly income comes from Mexican sources, OR if Mexico is your principal professional seat (main base of activities).
4. 4If either condition points to Mexico, you remain a Mexican tax resident regardless of how many days you spend abroad.

Examples

Example 1 — only home in Mexico

You rent and furnish an apartment in Mexico City as your only home, but travel for work most of the year and spend well under 183 days in Mexico. Because your only permanent home is in Mexico, you are a Mexican tax resident — the low day count does not matter.

Example 2 — two homes, income points to Mexico

You keep a home in Mexico and a rental in Portugal. More than half of your yearly income comes from Mexican clients. Your centre of vital interests is in Mexico, so you stay resident there even if you spend more days in Portugal.

Example 3 — genuine move abroad

You give up your Mexican home, move your family and main business abroad, and file the change-of-residence notice with SAT before leaving. With no home and no centre of vital interests in Mexico, you cease to be a Mexican tax resident.

Exceptions & edge cases

• Mexican nationals are presumed resident. Unless you can prove otherwise, the burden is on you to show your vital interests have moved abroad.
• Exit notice required. Giving up residency is not automatic — you must file a notice (aviso) with SAT no later than 15 days before the change of residence.
• Low-tax jurisdictions. Nationals who relocate to a listed preferential tax regime may be treated as Mexican residents for the year of the move and the following five years.
• Tax treaties. If you are resident in two countries, the applicable double-taxation treaty applies its own tie-breaker to assign a single treaty residence and divide taxing rights.

Common misconceptions

• "Under 183 days means I'm not resident." False — Mexico has no day rule; your home and centre of vital interests decide it.
• "Leaving Mexico ends my residency." Not by itself — you must file the departure notice with SAT, and nationals must prove their vital interests have genuinely moved.
• "Only Mexican-source income is taxed." Mexican tax residents are taxed on their worldwide income, subject to any applicable treaty.
• "Day counts are the test." They are supporting evidence at most — keeping a home and income base in Mexico is what keeps you resident.

Frequently asked questions

Sources

• SAT — Constancia de residencia para efectos fiscales
• Código Fiscal de la Federación — Artículo 9