UK savers earning interest from bank accounts, building society deposits, bonds or investment platforms face income tax on that interest unless it falls within specific allowances. The personal savings allowance shields most basic and higher-rate taxpayers from tax on modest interest earnings, while additional-rate taxpayers and those with substantial savings may owe tax at rates up to the higher or additional rate. Understanding which interest is taxable, which allowances apply, and how HMRC collects the tax ensures you stay compliant and avoid unexpected bills or penalties.

Which types of interest income are taxable in the UK?

Most interest you receive or that is credited to your account during the UK tax year is subject to income tax. Common taxable sources include:

  • Interest from bank and building society savings accounts and current accounts
  • Interest on fixed-term deposits and notice accounts
  • Corporate bond interest
  • UK government gilts (though some gilts may have specific tax treatment)
  • Peer-to-peer lending platform returns classified as interest
  • Certain unit trust and open-ended investment company distributions treated as interest
  • Interest on overseas savings accounts and foreign bank deposits (UK residents must declare worldwide interest income)

Interest earned within an Individual Savings Account (ISA) is entirely tax-free regardless of the amount, making ISAs one of the most tax-efficient homes for cash savings. Premium Bond prizes are also exempt from income tax. Some National Savings and Investments products offer tax-free interest, and interest awarded as part of compensation for personal injury may be exempt in specific circumstances. Always verify the tax status of any NS&I product on gov.uk, as rules can vary by product type.

If you hold a joint savings account, HMRC typically assumes the interest is split equally between account holders for tax purposes unless you can demonstrate that the underlying capital belongs in unequal shares and formally notify HMRC of the actual beneficial ownership.

What is the personal savings allowance and how does it work?

The personal savings allowance (PSA) allows UK taxpayers to earn a specified amount of interest each tax year without paying income tax on it. The size of your PSA depends on your marginal income tax rate:

  • Basic-rate taxpayers: individuals whose total taxable income (after deducting the personal allowance) falls within the basic rate band can earn up to a certain amount in interest tax-free each year. Check the current PSA limit for basic-rate taxpayers on gov.uk.
  • Higher-rate taxpayers: those whose income pushes them into the higher-rate band receive a reduced PSA. Verify the current higher-rate PSA on gov.uk.
  • Additional-rate taxpayers: individuals with income above the additional-rate threshold receive no PSA and must pay tax on every pound of interest income.

Your marginal rate is determined by your total taxable income from all sources (employment, self-employment, pensions, rental income, dividends and interest) after deducting your personal allowance. If your non-savings income alone already places you in the higher or additional rate band, your PSA will be correspondingly smaller or zero.

Interest within your PSA is taxed at a zero per cent rate, meaning it does not increase your tax bill. Interest above the PSA is taxed at your marginal income tax rate on savings income.

How do the personal allowance and starting rate for savings interact with interest income?

Every UK taxpayer is entitled to a personal allowance, which is the amount of income you can earn each tax year before any income tax is due. If your total income from all sources (wages, pensions, interest, dividends) does not exceed the personal allowance, you will not owe income tax on your interest or any other income.

There is also a starting rate for savings, which provides an additional band of tax relief for individuals with low total income. The starting rate for savings applies to a specific band of savings income and is taxed at zero per cent. However, this band is reduced by one pound for every pound of non-savings income (such as wages or pension) you earn above the personal allowance. In practice, if your earned income already uses up the personal allowance plus the full starting rate band, the starting rate for savings will not provide any additional relief.

For example, if you have modest earned income that only partially uses your personal allowance, any remaining headroom plus the starting rate band can shelter interest income from tax before the PSA even comes into play. Always check the current starting rate band and personal allowance figures on gov.uk, as these thresholds are subject to change and may be frozen or adjusted by government policy.

At what rates is interest income taxed and how is it collected?

Interest income is classified as savings income for UK tax purposes. Savings income is taxed after non-savings income (employment, pensions, trading profits) but before dividend income in the income tax calculation hierarchy. This ordering can be important because it determines which rate bands apply to your interest.

Once your interest exceeds your PSA and any starting rate relief, it is taxed at the savings income tax rates corresponding to your marginal band:

  • Interest falling within the basic rate band is taxed at the basic rate for savings income.
  • Interest that pushes your total income into the higher rate band is taxed at the higher rate for savings income.
  • Interest that takes you into the additional rate band is taxed at the additional rate for savings income.

Verify the current savings income tax rates on gov.uk. Be aware that future changes to these rates may be announced in government budgets, so always confirm the rates applicable to the tax year in question.

Most UK banks and building societies now pay interest gross, meaning no tax is deducted at source. You receive the full interest amount, and it is your responsibility to report and pay any tax due. HMRC collects tax on savings income in one of two ways:

  • Self Assessment: if you complete a Self Assessment tax return (for example, because you are self-employed, a landlord, or have other untaxed income), you must declare all taxable interest on the return. HMRC will calculate the tax due and include it in your balancing payment.
  • PAYE tax code adjustment: if you are employed or receive a pension and do not file Self Assessment, HMRC may adjust your tax code to collect tax on your interest through Pay As You Earn. This spreads the tax liability across the year by reducing your tax-free pay each month.

If your interest income is modest and falls entirely within your personal allowance and PSA, you do not need to take any action or notify HMRC. However, if you receive a significant amount of interest and are not in Self Assessment, HMRC may contact you or issue a tax code change. It is good practice to keep records of all interest received in case HMRC requests information.

Do I need to declare interest from overseas accounts?

Yes. UK residents are liable to UK income tax on their worldwide income, including interest earned on foreign bank accounts, overseas bonds, and foreign investment platforms. You must declare this interest on your Self Assessment tax return even if tax has already been withheld by the foreign country.

Many countries have double taxation agreements with the UK, which means you can usually claim foreign tax credit relief to avoid being taxed twice on the same income. The relief is limited to the lower of the foreign tax paid or the UK tax due on that income. Keep evidence of any foreign tax withheld (such as certificates from the foreign bank) to support your claim.

Failing to declare overseas interest can result in penalties and interest charges from HMRC. If you hold foreign accounts or assets, ensure you understand your reporting obligations, including any requirements under the Common Reporting Standard or other international information exchange agreements.

How is interest on children's savings taxed?

Interest earned on savings held in a child's own name is generally treated as the child's income for tax purposes. Most children have little or no other income, so their interest will usually fall within their own personal allowance and be tax-free.

However, special anti-avoidance rules apply when a parent gifts money to their own child (under 18 and unmarried). If the interest arising from that parental gift exceeds a de minimis threshold per parent per child per tax year, the entire interest amount is taxed as the parent's income, not the child's. Check the current de minimis limit on gov.uk.

This rule applies per parent, per child. For example, if both parents each give money to the same child and each gift generates interest above the threshold, both parents must declare the respective interest as their own income. Gifts from grandparents, other relatives, or family friends are not caught by this rule and remain taxable as the child's income (usually tax-free due to the child's personal allowance).

Junior ISAs are an exception: interest and gains within a Junior ISA are always tax-free, regardless of who contributed the money, making them a tax-efficient vehicle for children's savings.

What records should I keep and what are the penalties for non-compliance?

You should retain records of all interest received during the tax year. This includes:

  • Annual interest statements from banks and building societies
  • Contract notes or statements from bond issuers and investment platforms
  • Records of interest credited to overseas accounts, including any foreign tax withheld
  • Evidence of the source of funds in joint accounts if you wish to claim an unequal split

HMRC can request evidence of your interest income, and you may need these records to complete your Self Assessment return accurately or to query a PAYE code adjustment. Keep records for at least five years after the 31 January Self Assessment filing deadline for the relevant tax year (longer if you are in Self Assessment and HMRC opens an enquiry).

Failure to declare taxable interest can result in penalties and interest charges. HMRC may impose a penalty based on the amount of tax underpaid and the reason for the failure (careless, deliberate, or deliberate and concealed). Interest on unpaid tax accrues from the original due date until the tax is paid. If you discover an error or omission, notify HMRC as soon as possible to minimise penalties under the disclosure rules.

Frequently asked questions

Do I pay tax on interest if I earn below the personal allowance?

No. If your total income from all sources (including interest) is less than the personal allowance for the tax year, you will not owe any income tax. Your interest is effectively tax-free in this scenario, and you do not need to report it to HMRC.

Can I split interest from a joint account differently from 50/50 for tax purposes?

Yes, but only if the underlying capital in the account belongs to the account holders in unequal shares and you formally notify HMRC of the actual beneficial ownership. You will need to complete and submit a Form 17 (for married couples or civil partners) or provide equivalent evidence for other joint account holders. Without such notification, HMRC will assume a 50/50 split.

Is interest earned in an ISA taxable?

No. All interest, dividends and capital gains earned within an ISA wrapper are completely tax-free, and you do not need to declare ISA income or gains on a tax return. ISAs do not count towards your personal savings allowance because the income is exempt, not merely relieved.

What happens if my interest income pushes me into a higher tax band?

Interest is taxed after your non-savings income in the calculation order. If your total income (non-savings income plus interest) exceeds the basic rate threshold, the portion of interest that falls into the higher rate band will be taxed at the higher rate for savings income. This can mean that part of your interest is taxed at the basic rate and part at the higher rate, depending on where it falls in your overall income stack.

Will HMRC automatically know about my interest income?

UK banks and building societies report interest paid to customers directly to HMRC. HMRC uses this information to check tax returns and adjust PAYE codes. However, you remain responsible for declaring all taxable interest, especially from overseas accounts or platforms that may not report automatically. If HMRC identifies undeclared interest, they may open an enquiry or issue a tax assessment.

Are Premium Bond prizes taxable?

No. Prizes from NS&I Premium Bonds are exempt from UK income tax and capital gains tax. You do not need to declare Premium Bond winnings on a tax return, regardless of the amount won.

How MPS Accountancy can help you manage tax on savings income

Navigating personal savings allowances, starting rate bands, PAYE code adjustments and Self Assessment reporting can be complex, especially if you have multiple income sources, overseas accounts, or significant interest income. Our team at MPS Accountancy works with individuals across the West Midlands and throughout the UK to ensure your savings income is reported accurately and tax-efficiently.

We can review your overall income position, confirm which allowances and reliefs you are entitled to, advise on tax-efficient savings vehicles such as ISAs, and handle all Self Assessment filing and correspondence with HMRC on your behalf. If you have received interest from foreign accounts, we can help you claim double taxation relief and meet your reporting obligations.

For personalised advice on how to minimise tax on your interest income and keep your affairs compliant, contact our team today or explore our Self Assessment services and tax planning support.