Tax on savings interest: do you need Self Assessment?

You can owe UK tax on bank or investment interest without automatically needing a Self Assessment tax return. The first job is to work out how much taxable interest you received, which Income Tax band you fall into and which savings allowances are available.

For 2026 to 2027, the Personal Savings Allowance remains:

• £1,000 for basic-rate taxpayers;
• £500 for higher-rate taxpayers;
• £0 for additional-rate taxpayers.

There can also be a starting rate for savings of up to £5,000 for people with relatively low other income.

What counts as savings interest?

HMRC's guidance includes interest from sources such as:

• bank and building-society accounts;
• savings and credit-union accounts;
• certain bonds;
• peer-to-peer lending;
• some investment funds;
• some life-insurance or annuity arrangements.

Interest inside tax-free accounts such as ISAs does not normally use your Personal Savings Allowance.

Foreign savings interest has additional rules and may need to be reported as foreign income.

Your tax band is calculated including the interest

Do not decide your Personal Savings Allowance by looking only at your salary before adding the interest.

HMRC says you work out the band by adding savings interest to your other income. A person close to the higher-rate threshold can therefore have an allowance different from the one they expected when looking at salary alone.

The starting rate for savings

People with low non-savings income may also qualify for a starting rate for savings of up to £5,000.

HMRC says you are not eligible for it if your other income is £17,570 or more. Below that level, the £5,000 starting-rate band is reduced by £1 for every £1 of other income above the Personal Allowance.

This is separate from the Personal Savings Allowance.

If your interest is above the allowance

Tax is due on the interest above the available allowances at your normal Income Tax rate.

How the tax is collected depends on your situation.

If you already complete Self Assessment

Report the savings interest on your tax return. This applies, for example, if you are self-employed and already file a return for your business income.

If you are employed or receive a pension

HMRC can normally adjust your PAYE tax code to collect tax on savings interest. HMRC uses information from banks and building societies and may estimate current-year interest using earlier information.

If you are over your allowance and have not received a tax calculation or adjustment by 31 March following the tax year, HMRC says you should contact them.

If you are not in PAYE or Self Assessment

Banks and building societies report interest information to HMRC. HMRC can then tell you if tax is due and how to pay it.

When does savings income itself require Self Assessment?

HMRC currently says you need to register for Self Assessment if your income from savings and investments is over £10,000.

Below that figure, Self Assessment may still be required for another reason. For example, you might also have rental income, foreign income, self-employment or capital gains.

Joint accounts

HMRC normally splits interest from a joint account equally between account holders unless a different split applies and HMRC is told about it.

This can matter when one holder is a basic-rate taxpayer and the other pays a higher rate.

High income can change more than the savings allowance

If your adjusted net income exceeds £100,000, the Personal Allowance is gradually withdrawn. That can make a savings-interest calculation more complicated than simply applying the £500 higher-rate allowance.

Pension contributions, Gift Aid and other components of adjusted net income can also matter.

A practical example

Suppose you are a higher-rate taxpayer and receive £1,400 of taxable savings interest.

With a £500 Personal Savings Allowance, £900 may be taxable, subject to the rest of your circumstances. That does not necessarily mean you must start Self Assessment purely because of the £900. HMRC may be able to collect it through PAYE.

Now suppose your total savings and investment income is £12,000. HMRC's current guidance says the £10,000 registration threshold is exceeded, so Self Assessment becomes relevant in its own right.

What should you gather before asking for help?

Collect:

1. annual interest certificates or bank statements;
2. interest from every taxable account, not just your main bank;
3. employment and pension income;
4. dividend or investment income;
5. foreign interest separately;
6. any HMRC tax-code or calculation letters;
7. whether you already submit Self Assessment.

Banks reporting interest to HMRC is useful, but it is not a substitute for knowing your own figures. HMRC may receive information from several sources while you remain the person responsible for making sure the tax position is correct.