Tax residency

Tax residency is the legal status that determines where you tax your worldwide income. Each country defines its criteria; Spain uses Art. 9 LIRPF.

You're a Spanish tax resident if you meet at least ONE of these:

1. Stay >183 days in Spanish territory during the calendar year (including sporadic absences, unless you prove tax residency elsewhere).
2. Center of economic interests in Spain (core of activities or economic interests directly or indirectly, see its entry).
3. Non-separated spouse and/or minor children reside in Spain (presumption unless proven otherwise).

How to stop being a Spanish tax resident:

• Spend <183 days/year (with verifiable flight tickets and immigration prints).
• Obtain a tax residency certificate in another country.
• Cut center of interests (move company, family, accounts).
• File Modelo 030 notifying the tax address change.
• Keep Modelo 720 if you leave Spanish assets.

Every country has its own criteria; Anglo-Saxon countries typically use the "183-day test" (UK, USA with its nuances), Latin countries weigh center-of-interests more.