Why Spanish inheritance law surprises foreign residents
Spain applies a forced-heirship system (herencia forzosa) by default: a fixed portion of your estate is reserved by law for specific family members — typically children — regardless of what your will says. This is a fundamentally different starting point from the US and UK, where testamentary freedom generally lets you leave your estate to whomever you choose. If you own property or hold assets in Spain and haven't addressed this, Spanish law can apply to your estate by default once you're habitually resident here.
Clients often assume that having a will in their home country is enough. It isn't automatic — without an explicit choice-of-law clause, Spanish courts and notaries will typically default to applying Spanish succession rules to a habitual resident's estate.
The Brussels IV fix: choosing your own law
EU Regulation 650/2012, widely known as Brussels IV, lets you choose the law of your own nationality to govern the succession of your estate, instead of the law of your country of habitual residence. Critically, this option isn't limited to EU citizens — Article 22 of the regulation allows any person, regardless of nationality, to elect the law of a country whose nationality they hold. That means US and UK citizens living in Spain can validly choose US state law or UK law to govern who inherits their Spanish assets, overriding Spain's forced-heirship rules.
To make this election, you need an explicit choice-of-law clause in your will — ideally a single, clearly worded sentence naming the law you're choosing. Courts have generally honored a clear express choice; relying on the will's general tone to imply your intent is a much weaker position and invites disputes among heirs.
What Brussels IV does not change
This is the point that trips people up most: choosing your national law only decides who inherits and how much. It has no effect on Spanish inheritance tax, which is a completely separate legal question. Spanish inheritance tax (Impuesto de Sucesiones) still applies to Spanish-situated assets — and often to worldwide assets, depending on your tax residency — regardless of which country's succession law governs the distribution. The two questions run on entirely separate tracks: one European regulation, one Spanish tax code, and choosing your own succession law under Brussels IV does nothing to reduce the tax bill.
Spanish inheritance tax is also largely administered at the regional (autonomous community) level, and rates and allowances differ meaningfully between regions — a fact that matters for anyone with property in more than one part of Spain, or considering where to buy.
Making this work in practice
The practical sequence for most US and UK clients is: draft or update a will with an explicit Article 22 choice-of-law clause, keep that will consistent with any separate will you hold in your home country (to avoid the two documents contradicting each other), and get an inheritance tax projection based on your actual Spanish assets and region so there are no surprises for your heirs later. This is squarely a job for a specialist who works across both systems — Spanish inheritance tax rules interact with US and UK estate planning in ways that are easy to get wrong from either side alone — the same cross-border complexity covered in our FATCA and Spanish tax residency guide.