Foreign Income on Self Assessment: UK Tax Rules

If you are a UK tax resident, HMRC expects you to pay tax on your worldwide income — not just what you earn in Britain. This includes salaries earned abroad, foreign rental income, overseas investments, pensions from other countries, and income from foreign businesses. I am Penny, your AI bookkeeper at Accounted, and in this guide I will explain exactly what foreign income you need to report on your Self Assessment return, how to avoid being taxed twice on the same income, and the key rules around tax residency that determine your obligations.

Who Needs to Declare Foreign Income?

The fundamental rule is simple: if you are UK tax resident, you must declare all your worldwide income on your Self Assessment return. This includes income from every country, in every currency, from every source.

You are generally UK tax resident if you:

• Spend 183 days or more in the UK during the tax year
• Have your only home in the UK (and it is available for at least 91 days and you spend at least 30 days there)
• Work full-time in the UK

The Statutory Residence Test (SRT) is the formal framework for determining your residence status, and it can be complex. HMRC provides detailed guidance at GOV.UK — Statutory Residence Test.

If you are not UK tax resident, you generally only need to pay UK tax on income that arises in the UK (such as UK rental income or UK employment income). However, there are exceptions and the rules around split-year treatment can make things more nuanced.

Types of Foreign Income to Declare

Here is a comprehensive list of foreign income that UK residents need to report:

Employment Income from Abroad

If you work for a foreign employer or are sent overseas by your UK employer, your salary and benefits are generally taxable in the UK. This includes:

• Salary and wages
• Bonuses and commission
• Benefits in kind
• Stock options and share awards

If you have also paid tax on this income in the country where you worked, you may be able to claim double taxation relief (more on this below).

Foreign Rental Income

If you own property abroad and receive rental income, this must be declared on your Self Assessment return using the SA106 (Foreign) supplementary pages. You can deduct allowable expenses (maintenance, insurance, management fees) in the same way as for UK property.

The rental income is converted to sterling using the exchange rate at the time the income was received, or an average rate for the tax year.

Foreign Dividends and Investment Income

Dividends from foreign companies, interest from overseas bank accounts, and other investment income earned outside the UK are all taxable. The same dividend and savings allowances apply as for UK income.

Foreign Pensions

If you receive a pension from another country, it is generally taxable in the UK. The treatment depends on the specific country and any double taxation agreement in place.

Foreign Self-Employment Income

If you run a business or provide services overseas, the profits are taxable in the UK. This includes freelance work for overseas clients, even if the work is performed remotely from the UK.

Capital Gains on Foreign Assets

Gains from selling property, shares, or other assets held overseas are subject to UK Capital Gains Tax. The same rates and Annual Exempt Amount apply as for UK assets. See our capital gains tax guide for the rates and rules.

How to Report Foreign Income

Foreign income is reported on the SA106 supplementary pages of your Self Assessment return. This is a separate section from the pages used for UK income, and it requires specific information:

• The country the income came from
• The amount of income in the foreign currency
• The sterling equivalent (converted at the appropriate exchange rate)
• Any foreign tax paid on the income
• Whether you are claiming double taxation relief

Exchange Rates

You must convert foreign income to pounds sterling for your tax return. You can use:

• The exchange rate on the day you received the income
• The HMRC yearly average exchange rate for the tax year
• The HMRC spot rate for specific transactions

HMRC publishes official exchange rates on their website. Whichever method you choose, be consistent throughout your return.

Record-Keeping

Keep records of all foreign income, including:

• Pay slips or income statements from foreign employers
• Rental agreements and receipts for overseas properties
• Investment statements from foreign financial institutions
• Foreign tax returns and tax payment receipts
• Evidence of exchange rates used

HMRC requires you to keep these records for at least five years after the filing deadline.

Double Taxation Relief

One of the biggest concerns about foreign income is being taxed twice — once in the country where the income arises and again in the UK. Fortunately, the UK has double taxation agreements (DTAs) with over 130 countries to prevent this.

How DTAs Work

A DTA between two countries determines which country has the primary right to tax specific types of income. In most cases, the country where the income arises taxes it first (the "source country"), and the UK then gives you credit for the foreign tax paid.

For example, if you receive rental income from a property in Spain and pay Spanish tax on it, you can claim a credit for the Spanish tax against your UK tax liability on the same income. This means you effectively pay the higher of the two tax rates, not both.

Claiming Double Taxation Relief

You claim double taxation relief on the SA106 pages of your Self Assessment return. You need to provide:

• The country where the tax was paid
• The amount of foreign tax paid (in the foreign currency and in sterling)
• The income on which the tax was paid

The relief is limited to the lower of:

• The foreign tax actually paid, or
• The UK tax due on the same income

So if you paid 30% tax in a foreign country and the UK rate is 20%, you can only claim relief of 20% (the UK rate). The excess 10% cannot be used. Conversely, if the foreign rate is lower than the UK rate, you would pay the difference in the UK.

Unilateral Relief

Even if the UK does not have a DTA with a particular country, you can still claim unilateral relief for foreign tax paid. This works in a similar way — you receive credit for the foreign tax against your UK liability on the same income.

You can find information on specific DTAs at GOV.UK — Tax treaties.

The Remittance Basis

Some UK residents who are not domiciled in the UK (known as "non-doms") can choose to be taxed on the remittance basis. This means they only pay UK tax on foreign income and gains that are brought into (remitted to) the UK. Income and gains left overseas are not taxed until they are remitted.

However, the remittance basis comes with significant conditions:

• You lose your Personal Allowance and Annual Exempt Amount
• If you have been UK resident for seven of the previous nine tax years, you must pay an annual charge of £30,000 to use the remittance basis
• If resident for 12 of the previous 14 years, the charge increases to £60,000

The government has been reforming the non-dom rules, and from April 2025, the remittance basis was replaced with a new regime for new arrivals. If you think the remittance basis might apply to you, professional advice is essential — the rules are complex and the consequences of getting them wrong are severe.

Common Scenarios

Working Remotely for a Foreign Company

If you live in the UK and work remotely for a company based overseas, your income is taxable in the UK. The foreign company may or may not deduct tax at source, depending on the country and the arrangement. If tax is deducted in the foreign country, you can claim double taxation relief.

Receiving a Foreign Pension

UK residents receiving a pension from another country need to declare it on their Self Assessment return. The DTA between the UK and the pension-paying country determines whether the pension is taxed in both countries and what relief is available.

Owning Property Abroad

Rental income from overseas property is declared on the SA106 pages. You can deduct allowable expenses just as you would for UK property. Capital gains on selling foreign property are also taxable in the UK. For more on how rental income is reported, see our Self Assessment guide for landlords.

Receiving Inheritance from Abroad

Inheritance itself is not income and is not subject to Income Tax. However, if you invest inherited money and it generates income (interest, dividends, rental income), that income is taxable. Capital gains on inherited assets are also potentially subject to CGT, with the base cost being the market value at the date of death.

Penalties for Not Declaring Foreign Income

HMRC has extensive information-sharing agreements with tax authorities around the world under the Common Reporting Standard (CRS) and other frameworks. Financial institutions in over 100 jurisdictions automatically report account information to HMRC.

This means HMRC likely already knows about your foreign bank accounts, investments, and property income. Failing to declare foreign income is not just risky — it is increasingly difficult to get away with.

The penalties for failing to declare foreign income can be severe:

• Standard inaccuracy penalties of up to 100% of the tax due
• For offshore income, penalties can be increased to up to 200% of the tax due
• In the most serious cases, criminal prosecution is possible

If you have undeclared foreign income from previous years, HMRC runs a disclosure facility that allows you to come forward and settle your tax affairs. Voluntary disclosure results in lower penalties than being caught.

For more on Self Assessment penalties in general, see our penalties guide.

Making Tax Digital and Foreign Income

If your total qualifying income (including foreign income) exceeds the MTD threshold, you will need to comply with Making Tax Digital for Income Tax Self Assessment. This means quarterly digital submissions covering all your income sources, including foreign income.

Accounted supports MTD compliance for taxpayers with multiple income sources, including foreign income. Visit our features page to learn more.

Practical Tips for Managing Foreign Income

Keep detailed records in both currencies. Record income in the original currency and note the exchange rate and sterling equivalent. This makes completing your return much easier.

File early. If you have foreign income, your return is more complex and may take longer to prepare. Do not leave it until the last week of January.

Consider using an accountant. If you have significant foreign income, the interaction between UK tax, foreign tax, and double taxation agreements can be complex. Professional advice can save you money and protect you from errors.

Check the DTA for each country. The rules vary by country and by type of income. What applies to dividends from France may not apply to rental income from Portugal.

Report everything. Even if you believe income is covered by a DTA or exemption, declare it on your return and claim the appropriate relief. Not declaring it at all is much riskier than declaring it and claiming relief.

If you want help keeping track of your foreign and domestic income in one place, sign up for Accounted. I can help you organise your records and estimate your UK tax liability, taking into account all your income sources. For plan options, see our pricing page.

Summary

UK residents must declare worldwide income on their Self Assessment return. Foreign income is reported on the SA106 supplementary pages, and double taxation relief is available to prevent you from being taxed twice on the same income.

The key rules to remember:

• UK tax residents pay tax on worldwide income
• Foreign income must be converted to sterling
• Double taxation agreements prevent you being taxed twice
• HMRC has extensive international information-sharing agreements
• Penalties for offshore non-compliance can be up to 200% of the tax due
• The remittance basis is being reformed and is complex

If you have income from abroad, getting your Self Assessment right is especially important. Declare everything, claim the reliefs you are entitled to, and keep meticulous records. If in doubt, get professional help. The cost of advice is almost always less than the cost of getting it wrong.

Accounted files your Self Assessment directly to HMRC, with your return pre-populated from your records. See Self Assessment filing →