Tax Obligations for British Citizens in Spain: The UK Treaty and What to File

For a British national settling in Spain, the tax picture has two layers that need to be understood separately before they can be managed together: the Spanish regime that applies in Spain, and the bilateral treaty that coordinates the two jurisdictions. Conflating the two leads people to assume they either pay nowhere or pay in both, when the reality is more nuanced and, with the right planning, manageable.

The UK-Spain Double Taxation Treaty: What It Regulates

The treaty survived Brexit intact

The Convention between the United Kingdom and Spain for the Avoidance of Double Taxation dates from 1975, with later amending protocols. It remains fully in force after Brexit — bilateral tax treaties were not affected by the UK's departure from the EU — and establishes which country has primary taxing rights over each type of income.

Income by income: where each type is taxed

| Type of income | Primary taxing jurisdiction | |----------------|----------------------------| | Employment income (Spanish employer) | Spain | | Remote work from Madrid for UK employer | Spain (generally) | | Dividends from UK companies | Spain (UK withholding capped at 15%, offsetable) | | Bank interest | Spain | | Business profits (UK company, no permanent establishment in Spain) | United Kingdom | | UK public service pension (civil servants, military, police) | United Kingdom | | UK State Pension (standard) | Spain (if Spanish tax resident) |

The exception that surprises most people: pensions from UK public service employment are taxed in the UK regardless of where the recipient lives. The standard State Pension, however, is taxed in Spain if you are a tax resident there.

How the treaty prevents double taxation in practice

When income arises in the UK and is also taxable in Spain, the treaty assigns taxing rights. The country without primary rights either exempts the income or grants a credit for the tax paid in the other country. The Agencia Tributaria allows UK withholding tax to be offset against the Spanish tax on the same income, so it is not paid twice — it is allocated between the two countries.

When You Stop Being a UK Tax Resident

The Statutory Residence Test

The UK applies the Statutory Residence Test (SRT) to determine whether someone is or remains a UK tax resident. The test weighs:

• Number of days spent in the UK during the tax year
• Ties to the country: available home, family, employment
• Years of prior UK residency

For most British nationals who relocate to Madrid definitively, UK tax residency ceases when they spend fewer than 16 days in the UK in a tax year (or fewer than 46 if not resident in the three prior years). The UK tax year runs April to April — different from Spain's calendar year — which creates a period of overlap in the year of departure.

Formalizing the departure

Deregistering as a UK tax resident is documented through:

• Form P85: filed with HMRC if you are an employee with a UK employer
• Departure year self-assessment return: covers the period as a resident in the UK
• Short Tax Return for the partial period: if there is no full year of UK income after departure

HMRC does not have an explicit "deregistration" procedure in the way some European countries do, but filing the P85 and the departure year return documents the change. This should be done before the first Spanish IRPF return is filed to avoid any overlap in residency claims.

Tax Obligations in Spain from Year One

IRPF: when you must file

Once you are a Spanish tax resident — more than 183 days in the calendar year, or with the core of your economic interests here — the main obligation is the annual IRPF return filed with the Agencia Tributaria. Filing is mandatory when:

• Employment income exceeds 22,000 euros from a single payer
• Employment income exceeds 15,000 euros from multiple payers
• Capital returns exceed 1,500 euros
• Property income from owned real estate exceeds 1,000 euros

The tax scale in Madrid is progressive and reaches 43.5% above 300,000 euros. For high earners the impact can be significant, and evaluating whether the Beckham Law impatriates regime applies before the move can make a material difference.

The year of transition: double exposure

The year of relocation requires particular care. You can be a tax resident in both countries during different parts of the same calendar year. In Spain, a partial-year return can cover only the months of effective residency. In the UK, the departure year self-assessment covers the period before leaving. Coordinating both declarations — and applying the treaty's tie-breaker rules if there is an overlap — is the most complex part of year one.

The Modelo 720: What It Is and Who Must File It

Who is obliged

The modelo 720 is an informational declaration of assets and rights held abroad. It does not generate a direct tax payment, but failure to file it carries penalties. It is mandatory for Spanish tax residents who hold:

• Foreign bank accounts with a balance above 50,000 euros per institution
• Foreign real estate with a value above 50,000 euros
• Foreign securities, insurance and investments with a value above 50,000 euros per category

For a British national who retains a UK property after moving to Spain, the modelo 720 is almost certainly required — UK property values typically exceed this threshold by a significant margin.

Deadlines and consequences

The filing window is between 1 January and 31 March of the year following the first year of Spanish tax residency. It only needs to be filed again in subsequent years if the value of any category of assets changes by more than 20,000 euros from the last declared figure. The 2026 penalties framework is considerably more moderate than the original one declared partly incompatible with EU law in 2022, but non-compliance still carries material risk.

The general logic of tax residency transfer has strong parallels with EU citizens; the guide on transferring tax residency to Spain for EU citizens covers the shared principles.

For those relocating for professional reasons, the complete guide for British citizens in Madrid also covers visa and initial registration implications.

Frequently asked questions

Can a British citizen in Spain remain a UK tax resident?

Yes, if they spend enough days in the UK under the Statutory Residence Test — generally more than 183 days per year — or maintain sufficient ties to the country. However, spending more than 183 days in Spain in a calendar year makes Spain a tax resident regardless of the SRT outcome. When both countries claim residency simultaneously, the treaty's tie-breaker rules apply: they look at permanent home, center of vital interests, habitual abode and nationality, in that order.

Does a British resident in Spain need to declare their UK property to Spain?

Yes, in two distinct ways. First, via the modelo 720 (informational declaration of foreign assets) if the property value exceeds 50,000 euros — which applies to most UK properties given current market levels. Second, if the property generates rental income, those rents must be included in the Spanish IRPF return. The UK withholding tax on those rents can be offset against the Spanish tax due on the same income under the treaty.

Can a British national in Spain apply for the Beckham Law?

Yes. The impatriates regime does not discriminate by nationality. A British national who arrives in Spain under an employment contract with a Spanish company, or relocated by a foreign employer with a permanent establishment in Spain, can elect the flat 24% rate on employment income up to 600,000 euros. The requirements — no Spanish tax residency in the ten prior years and application within six months of starting work — are the same as for any other nationality. See our guide on the Beckham Law for British workers.

At Aedara, we coordinate fiscal relocation planning for British nationals, including the year-of-transition return. Contact us before you arrive and we will prevent the surprises.