Double Taxation Agreement UK-Spain: Avoiding Paying Tax Twice

What Is the Double Taxation Agreement?

The Double Taxation Agreement (DTA) between the United Kingdom and Spain is a bilateral treaty that prevents you from being taxed on the same income in both countries. Formally titled the "Convention between the United Kingdom of Great Britain and Northern Ireland and the Kingdom of Spain for the avoidance of double taxation and the prevention of fiscal evasion with respect to taxes on income and on capital," the current version was signed on 14 March 2013 and entered into force on 12 June 2014.

Without this agreement, a UK citizen living in Spain could theoretically be taxed by the UK (as a UK national with UK income sources) and by Spain (as a Spanish tax resident). The DTA sets out clear rules for which country has the right to tax each type of income.

How the DTA Works in Practice

The DTA operates on a simple principle: for each type of income, it assigns taxing rights to one or both countries. There are three possible outcomes:

• Exclusive taxing rights: Only one country may tax the income. The other country must exempt it. Example: private pension income is taxed only in Spain if you live there.
• Shared taxing rights with credit: Both countries may tax the income, but the country of residence must give a credit for tax paid in the other country. Example: rental income from UK property.
• Shared taxing rights with a cap: Both countries may tax, but the source country is limited to a maximum rate. Example: dividends (limited to 10% or 15% in the source country).

Determining Your Country of Residence

The DTA only applies if you are a tax resident of one country but have income arising in the other. If you are tax resident in both countries under their domestic law (a "dual resident"), the DTA contains tie-breaker rules to determine which country treats you as resident for treaty purposes. The tie-breakers are applied in this order:

• Permanent home: Where do you have a permanent home available? If only in one country, you are resident there.
• Centre of vital interests: Where are your personal and economic relations closer? Family, social connections, work, investments.
• Habitual abode: Where do you spend more time?
• Nationality: If still tied, the country of your nationality.
• Mutual agreement: If still tied, the tax authorities of both countries negotiate.

Which Country Taxes What: A Complete Breakdown

Employment Income

If you are employed in Spain by a Spanish company, your salary is taxed in Spain. The UK has no taxing rights. If you are employed by a UK company but work physically in Spain, Spain has the primary right to tax your employment income, but only if you spend more than 183 days in Spain in the fiscal year, or the employer has a permanent establishment in Spain, or the salary is paid by or on behalf of an employer in Spain.

If you spend fewer than 183 days working in Spain and your employer has no Spanish presence, the UK retains taxing rights. This is relevant for remote workers spending part of the year in Spain.

Self-Employment and Business Profits

Business profits are taxed in the country of residence unless you have a permanent establishment (establecimiento permanente) in the other country. A permanent establishment includes a fixed place of business — an office, workshop, or branch.

If you are a UK-registered sole trader or partnership and you do all your work remotely from Spain, Spain will tax your worldwide income as a Spanish tax resident. The UK cannot tax your business profits (unless you have a permanent establishment there). You may still need to file a UK tax return if you have UK-source income, but a credit is given for Spanish tax paid.

Rental Income from UK Property

This is where it gets complicated. Under the DTA, rental income from UK property can be taxed in both countries:

• UK: As the country where the property is located, the UK has the right to tax rental income. You will pay UK income tax at the non-resident rate (currently 20% basic rate for most landlords). You must file a UK Self Assessment return.
• Spain: As your country of residence, Spain also taxes your worldwide income, including UK rental income. You declare it on your Spanish tax return.
• Credit mechanism: To avoid double taxation, Spain gives you a credit for the UK tax paid. So if you owe €3,000 in Spanish tax on the rental income and you've already paid £2,000 in UK tax, you deduct the UK tax from your Spanish liability. You only pay the difference (if any) in Spain.

Important: You must actually pay the UK tax and have documentation to prove it. Spain will not give a credit for tax you could have paid but didn't. Register with HMRC as a non-resident landlord using form NRL1 if you want your letting agent to pay you gross (without deducting UK tax at source).

Capital Gains on UK Property

If you sell a UK property while living in Spain, both countries can tax the gain. Since April 2015, non-residents pay UK Capital Gains Tax on UK residential property disposals. The UK rate is 18% (basic rate) or 24% (higher rate) for residential property.

Spain, as your country of residence, also taxes the worldwide capital gain. The Spanish capital gains tax rates are:

• First €6,000: 19%
• €6,001 to €50,000: 21%
• €50,001 to €200,000: 23%
• €200,001 to €300,000: 27%
• Over €300,000: 28%

Again, Spain gives a credit for the UK CGT paid. If the UK rate is lower than the Spanish rate on the same gain, you pay the difference in Spain.

Pension Income

The DTA splits pensions into two categories:

• Private pensions (workplace pensions, SIPPs, personal pensions): Taxed only in Spain if you are Spanish tax resident. The UK must not deduct tax — submit form DT-Individual to HMRC.
• Government service pensions (civil service, Armed Forces, NHS, teachers, police, fire service): Taxed only in the UK. Spain exempts them but may use the income to calculate the rate on your other income (the "exemption with progression" method).

The UK state pension falls under the private pension rules — it is taxed only in Spain.

Dividends

Dividends from UK companies paid to a Spanish tax resident can be taxed in both countries, but the UK is limited to a maximum of 10% withholding (or 15% in some cases). Spain taxes the dividends as savings income at 19%-28%, but gives a credit for the UK tax withheld.

Interest

Interest from UK bank accounts or bonds is taxable only in Spain if you are Spanish tax resident. The UK does not withhold tax on interest paid to non-residents. You declare the interest on your Spanish tax return as savings income.

Royalties

Royalties are taxable only in the country of residence. If you earn royalties from UK intellectual property while living in Spain, only Spain can tax them.

Tax Credits and Relief Mechanisms

The DTA uses two main mechanisms to prevent double taxation:

1. Credit Method (Used by Spain)

Spain taxes your worldwide income but gives a credit for foreign tax paid. The credit is limited to the amount of Spanish tax that corresponds to the foreign income. In practice, this means you pay the higher of the two countries' rates on any given income.

2. Exemption Method (Used for Government Pensions)

Spain exempts government pension income from tax but may use the amount to determine the effective tax rate applied to your other income. This is called "exemption with progression." In practice, your government pension can push your other income into a higher tax bracket.

When You Become Spanish Tax Resident

You become Spanish tax resident if you meet any one of these three criteria:

• Physical presence: You spend more than 183 days in Spain during the calendar year (1 January to 31 December). Days of arrival and departure count as full days. Temporary absences are counted as days in Spain unless you can prove tax residency in another country.
• Centre of vital interests: Your main professional activities or business interests are in Spain, or the principal base of your activities is in Spain.
• Family ties: Your spouse (not legally separated) and/or minor children are resident in Spain. This creates a rebuttable presumption — you are assumed to be resident unless you can prove otherwise.

Spanish tax residency applies to the entire calendar year. Unlike the UK (which has a split-year treatment), Spain considers you resident for the full year if you meet the criteria at any point. This means that in the year you move, you could be considered tax resident in Spain for the whole year, even if you arrived in September.

Declaring UK Income in Spain

As a Spanish tax resident, you must declare all worldwide income on your annual Spanish tax return (Declaración de la Renta, filed between April and June for the previous calendar year). This includes:

• UK pensions (state and private)
• UK rental income
• UK bank interest and dividends
• UK capital gains
• UK employment or self-employment income
• Any other UK income

You must also file the Modelo 720 if you have assets abroad worth more than €50,000 in any category (bank accounts, investments, property). This is a disclosure form, not a tax return, but failure to file carries penalties of €5,000 per data item (reduced from the previous regime following an EU court ruling, but still significant).

Common Mistakes to Avoid

1. Not Claiming Relief in the UK

Many expats continue to have UK tax deducted from their pensions and never reclaim it. You need to actively apply — HMRC will not automatically stop deducting tax just because you've moved. Use form DT-Individual.

2. Forgetting to Declare UK Income in Spain

Some expats assume that because they've paid UK tax, they don't need to declare the income in Spain. This is wrong. You must declare all worldwide income in Spain, even if it has been taxed elsewhere. You then claim a credit for the foreign tax paid.

3. Misclassifying Pension Type

Confusing private and government pensions is a costly mistake. If you incorrectly treat a government pension as taxable only in Spain and don't pay UK tax on it, you face UK tax penalties. Conversely, if you incorrectly pay UK tax on a private pension, you're losing money unnecessarily.

4. Not Filing the Modelo 720

This catches many UK expats in their first year. If you have UK bank accounts, investments, or property worth over €50,000 in any category, you must declare them on the Modelo 720 by 31 March each year. The penalties for non-filing are severe.

5. Assuming the DTA Eliminates All Tax

The DTA prevents double taxation — it does not eliminate taxation. In most cases, you will pay the higher of the two countries' rates. Spain's income tax rates are generally higher than the UK's, so moving to Spain often means a higher overall tax bill.

6. Ignoring the Modelo 100 Credit

When filing your Spanish tax return (Modelo 100), ensure that your asesor fiscal correctly applies the deducción por doble imposición internacional (international double taxation deduction) in the relevant box. This is the mechanism by which you claim credit for UK tax paid.

Getting the DTA right is fundamental to your financial planning in Spain. The rules are logical but detailed, and the interaction between two countries' tax systems creates complexity. We strongly recommend using a bilingual tax adviser who understands both UK and Spanish tax law — the annual cost of professional advice (typically €300-€600 for a straightforward return) is a fraction of the tax savings they can generate.