Glossary
US–Spain Tax Glossary
Guides
Long-form explainers on residency, FBAR, IRPF, autónomo, and more.
Glossary
Plain-English definitions of the forms, rules, and concepts across both systems.
Blog
Founder notes, product updates, and posts on the US–Spain tax experience.
183-Day Rule The 183-day rule is Spain's primary day-count test for tax residency. If you spend more than 183 days in Spain during a calendar year, Spain will generally treat you as a tax resident for that year. Center of Economic Interests The center of economic interests is one of Spain's three tests for tax residency. If the main base of your economic activity or financial life is in Spain, Spain may treat you as a tax resident — even if you spend fewer than 184 days there. IRPF IRPF (Impuesto sobre la Renta de las Personas Físicas) is Spain's personal income tax. Spanish tax residents pay IRPF on their worldwide income. For Americans living in Spain, IRPF is the main Spanish tax obligation — and the one that interacts most directly with the US federal return. Modelo 100 Modelo 100 is Spain's annual income tax return for residents. Spanish tax residents file Modelo 100 to report their worldwide income to the Agencia Tributaria. For Americans in Spain, it is the closest Spanish counterpart to the US Form 1040. Tax Residency Tax residency is the legal status that determines whether a country can tax you as a resident — often on your worldwide income, not just income earned inside that country.