Certificates of interest and savings tax statements

A certificate of interest is a statement from a bank, building society or other savings provider showing how much interest it paid you over a tax year. Providers also call it an annual interest statement or a savings tax statement. HMRC may ask to see one, and it is the document most people reach for when they are filling in a Self Assessment tax return, claiming a tax refund, or proving their income for a benefits claim.

Most savers never need to do anything with one. Providers report the interest they pay to HMRC, and tax owing is usually collected automatically through your tax code¹. But the interest figures matter at certain thresholds: if your savings interest is more than £10,000, you must tell HMRC the amount on a Self Assessment tax return, and if you do not already complete one, you must register¹. A certificate is also the evidence you keep in case HMRC asks how you worked out what you owed².

What a certificate of interest shows

A certificate of interest is a simple document with one job: to state, in a form HMRC and others will accept, how much interest a particular account paid you during a particular tax year. It normally names the provider, identifies the account, gives the gross interest paid and states the tax year it covers. HMRC's own guidance on claiming relief tells taxpayers to get a certificate of interest from their lender showing the interest paid during the year, and warns that HMRC may ask to see it². The same principle applies to savings: the certificate is the evidence behind the figure you put on a form.

The figure on the certificate is gross interest, meaning interest before any tax. That matters because most savings interest is now paid without tax deducted, so the amount that landed in your account and the amount on the certificate are usually the same¹. Where a document asks for the interest you received, you enter that gross figure. HMRC's form P53Z, used when reclaiming tax after cashing in certain investments, asks for interest received and, for joint accounts, for your share of it, usually 50%⁵.

A certificate is not the same as a monthly statement. Monthly statements show interest credited in each month, which can straddle the 6 April tax year boundary. An annual certificate pulls the whole tax year together, which is what a tax return or a refund claim needs. If you hold several accounts, each provider issues its own certificate, and you add the figures together yourself.

Keep certificates for the tax year they cover. HMRC can open enquiries into returns, and the certificate is the proof of the interest figure you declared².

Savings certificates and mortgage certificates are different documents

The phrase "certificate" turns up in several corners of personal finance, and the documents are not interchangeable. An NS&I Savings Certificate is an investment in its own right: Index-linked Savings Certificates are a tax-free NS&I product that combines index-linking with a fixed term⁶. When one matures, you cash it in by printing and posting a cash-in form, or by writing to NS&I in Sunderland stating the amount from each certificate and how you want to be paid⁷. That certificate proves what you hold, not what interest you earned.

A mortgage certificate of interest is the opposite: it shows interest you paid rather than interest you earned. Lenders issue them so borrowers can claim relief where the rules allow it, and HMRC's help sheet tells you to get and keep one from your lender for the interest paid during the year². It has nothing to do with savings tax.

Separately, the word "certificate" also appears in mortgage advice. To give mortgage advice, an adviser must have completed a qualification called the Certificate in Mortgage Advice and Practice, known as CeMAP⁸. That is a professional qualification, not a document a consumer receives.

If you ask a provider for a "savings certificate" you may be sent details of an NS&I product rather than an interest statement, so it is safer to ask for an "annual interest statement" or a "certificate of interest for tax purposes".

What counts as savings income

Savings income is a legal term, not a loose description. HMRC's manuals define it by reference to legislation: "savings income" is defined in ITA07/S18⁹. In practice it covers interest from bank and building society accounts, interest from NS&I accounts that are not tax free, and interest from corporate bonds and similar sources. The definition matters because savings income gets its own tax bands and its own starting rate, which work differently from the rules on wages or rental income.

Interest inside an ISA does not count. ISAs are tax exempt accounts under which income received in the form of interest, dividends or capital gains is free of tax³. The range of things that can sit in the cash component of an ISA is set out in regulations: cash deposited with a building society or an authorised institution, units in a money market fund, and certain government securities¹⁰.

Foreign interest also counts, but it comes with extra rules. Interest on a foreign bank account is listed among qualifying foreign income, alongside overseas trade profits, overseas property business profits, dividends from non-UK resident companies and foreign pension income other than disqualified income¹¹. If you are registered for Self Assessment, you report interest there, and foreign interest can involve the foreign income and gains regime or foreign tax credit relief, which makes it more involved than UK interest¹¹.

For benefits purposes, the picture differs again. Pension Credit guidance works out qualifying income for Savings Credit in the same way as income for Guarantee Credit, but excludes certain payments including Incapacity Benefit, contribution-based Jobseeker's Allowance, contributory ESA, Severe Disablement Allowance, Maternity Allowance and maintenance payments¹². So the interest figure a benefits claim needs, and how it is treated, depends on which benefit is being claimed.

Accounts that do not get a certificate: ISAs and some NS&I products

Tax-free accounts do not need a certificate for tax purposes, because their interest is never reported as taxable income. The clearest case is the ISA. NS&I's Direct ISA, a cash ISA with a variable interest rate, states plainly on the question "Will you pay tax?": "No: this account is tax-free"¹³. NS&I does not offer a flexible ISA, so money taken out of its ISA cannot be put back within the same tax year¹⁴. Its Junior ISA is a cash Junior ISA, and NS&I does not offer a stocks and shares Junior ISA¹⁵.

NS&I's Index-linked Savings Certificates are also tax free⁶. Providers still send annual statements for these accounts, showing the interest or growth credited, and those statements are useful for your own records, but there is nothing to declare and no certificate needed for a return.

Taxable NS&I accounts are different. NS&I Income Bonds pay interest without deducting tax, but the interest is taxable and counts towards your Personal Savings Allowance¹⁶. Guaranteed Income Bonds work the same way: interest is added without tax deducted, but it is taxable and counts towards the allowance¹⁷. The Direct Saver is another ordinary taxable account¹⁸. NS&I's own complaints guidance lists examples of holdings that generate queries: individual Savings Certificates, Direct ISA accounts, Direct Saver accounts and Premium Bonds¹⁹. Premium Bonds pay prizes rather than interest, so there is no interest figure to certify at all.

The practical test is simple: if the interest counts towards your Personal Savings Allowance, it is taxable income and a certificate is the proof of it. If it does not, it is not. The guides to ISAs and to how tax on savings interest works cover the allowances in detail.

How to get a certificate online or in an app

For most providers, the quickest route is the one you already use for everyday banking. Where a provider offers an online service or an app, the annual interest figure is normally available to view, download and print, and many providers generate a certificate on demand rather than posting one automatically. NS&I's online and phone service lets customers manage savings online, including viewing details of their holdings²⁰. The same pattern of using an official digital service to produce a printable document appears across government: HMRC's child benefit proof service lets you use the online service or the HMRC app to print your "proof of entitlement" page or save it as a document to use as proof²¹.

A digital certificate is generally as good as a paper one for tax purposes. What matters is that it shows the provider, the account, the tax year and the gross interest. Downloading it yourself also means you are not waiting on the post, which matters if a deadline is close.

If you cannot find the statement in your app or online banking, the account may be one the provider treats differently, or the account may have closed since the tax year in question. Closed accounts are a common reason a certificate does not appear in the usual place, and the answer is to contact the provider directly, which the next section covers.

Getting a certificate by phone, in branch or by post

Providers that operate by phone and post, including NS&I, can produce certificates on request. NS&I's guidance for its online and phone service covers what to do when a paper document has gone missing: if you cannot find your certificate, write to NS&I with your full name and address and as many details about the investment as you can remember, and NS&I will send a replacement certificate²⁰. That process applies to NS&I certificates of holding; for an interest statement, the same contact routes work, by phone or in writing.

Branch-based banks and building societies can usually print an interest statement at the counter. Take identification. Credit unions, which some savers use as an alternative to banks, usually ask for two recent documents to prove identity and address, for example a passport, driving licence, student or work ID card, bus pass, birth certificate, bank statement or energy bill²². High street banks have their own rules, and guidance on opening, switching or closing accounts notes that if you have no passport or driving licence, a provider may accept other recent documents, typically under three months old, such as a Council Tax bill, utility bill, bank or credit card statement, an HMRC letter or tax statement, a mortgage statement, a tenancy agreement, a benefit or state pension statement, or a letter from your employer, college or training provider²³.

Allow time for the post. NS&I's guidance on buying Premium Bonds as a gift for someone else's child notes that identity checks can take up to four weeks from when proof of identity is received before the investment reaches the child²⁴. That is a different process, but it illustrates that document-heavy requests by post are not instant. Providers' own timescales for issuing interest certificates differ: guidance suggests within 10 working days, while some provider support pages say up to 14 working days, and the two figures have not been reconciled. If timing matters, ask the provider for the current timescale when you make the request.

One warning on copies. If a provider asks you to send a copy of an identity document rather than the original, NS&I's rules show how strict certification can be: copies of most documents on its lists must be certified, with the certifier writing "I certify that this a true and complete copy of the original [type of document] belonging to [your name]" on every page, in English, signed and dated on every page, with their full name, occupation, work address, daytime telephone number, official stamp where available and professional registration number if they have one²⁵. A GB passport or GB/Jersey driving licence copy is the exception and does not need certifying²⁵. An interest statement itself does not normally need this treatment: it is the provider's own document, not a copy of an identity document.

Joint accounts: tax on your share of the interest

Joint accounts do not change how interest is taxed in principle, but they do change whose income it is. Any interest earned in a joint account will usually be split equally between each person, with tax only due if a share is above the annual allowance²⁶. So a certificate for a joint account shows the whole interest figure, and each holder is responsible for their own half.

HMRC's forms work the same way. Form P53Z tells claimants: "If you have a joint account only enter your share, usually 50%, of the interest received"⁵. Each holder's share is then tested against their own allowance, and tax is paid on any interest over the allowance at that holder's usual rate of Income Tax¹.

The equal split is a default, not a rule of nature. If the money in the account actually belongs to one holder, HMRC must be told so the interest is treated as theirs rather than split²⁶. This can matter where one person funds the account and the other is only named on it.

Joint accounts also raise issues beyond income tax. If one holder dies, unless you were married or in a civil partnership, you might have to pay tax on some or all of the money in the account²⁶. And where jointly owned assets are sold rather than held, capital gains rules give each owner their own exempt slice: you are exempt from paying tax on the first £6,000 of your share if you own a possession with other people²⁸. The guides to joint savings accounts and FSCS cover on joint accounts cover the other practical points.

Using a certificate for your tax return

Most savers pay tax on savings interest without ever filling in a form. HMRC will usually collect the tax through your tax code if you are employed or get a pension, and will adjust the code to collect any tax you owe from the previous tax year¹. The certificate is not part of that process, but it is the figure you reach for when the process needs you.

The thresholds are where a certificate becomes necessary. If your savings interest is more than £10,000, you need to tell HMRC how much interest you earned on a Self Assessment tax return, and if you do not already complete one, you must register¹. If you already send a Self Assessment return, you report any interest earned on savings there, whatever the amount¹.

There is a deadline to watch. If you have tax to pay on your savings interest and do not get a letter from HMRC by 31 March of the following tax year, you must contact HMRC yourself¹. Waiting for a letter that never comes is not a defence.

The certificate also supports refund claims. Form P53Z, used to reclaim tax, asks for the interest received in the year, including your share of any joint account interest⁵. And the principle of keeping the provider's certificate as evidence runs through HMRC's guidance generally: its help sheet on interest relief tells taxpayers to make sure they get, and keep, a certificate of interest from their lender, because HMRC may ask to see it². The same discipline applies to savings interest.

Benefits claims are another use. Interest from savings counts as income for means-tested benefits, and the certificate is the document that proves how much that was. Pension Credit guidance excludes certain payments from qualifying income for Savings Credit, including Incapacity Benefit, contribution-based Jobseeker's Allowance, contributory ESA, Severe Disablement Allowance, Maternity Allowance and maintenance payments¹², so the interest figure and the other income figures are worked out separately. The guide to how savings affect Universal Credit and other benefits covers the capital rules.

Savings tax rates rise by 2 percentage points from April 2027

Anyone keeping certificates for future tax years should know that the rates applied to savings income are changing. From April 2027, the rates of income tax applicable to savings income increase by 2 percentage points across all bands⁴. The detail, confirmed in legislation and guidance, is:

• The savings basic rate rises from 20% to 22%²⁹
• The savings higher rate rises from 40% to 42%³⁰
• The savings additional rate rises from 47% at the top, up from 45%³⁰

The legislation behind this, section 3 of the Finance Act 2026, currently sets the savings higher rate at 40% for the tax year 2026-27³¹, which is the rate in force until the change takes effect on 6 April 2027³⁰. The increase was announced at Budget 2025, which set out increasing tax on property income and savings income by two percentage points at the basic, higher and additional rates³².

The change does not alter how interest is reported or how certificates work. It changes only the rate applied to savings income above your allowances. Two other changes arrive at the same time and interact with it: from April 2027 the personal allowance will be deducted against employment, trading and pension income first, before savings and dividend income, which changes how much savings income is actually taxed at these rates. The practical point for a certificate holder is that the interest figure on the certificate stays the same; the tax worked out from it does not.

Where to get help

If a provider will not issue a certificate, issues one with the wrong figure, or you cannot get the interest statement you need for a tax return, there are free places to turn. MoneyHelper, the government-backed money guidance service, covers everyday banking questions including joint accounts and dealing with providers²⁶. For tax questions, HMRC's guidance on how you pay tax on savings interest sets out the reporting rules and the 31 March deadline¹.

If a complaint to a provider about its documents or figures is not resolved, the Financial Ombudsman Service can look at it. Where the ombudsman tells a business to pay interest as part of an award, the business should deduct income tax from it at the basic rate before paying, pay the tax directly to HMRC and give you a tax deduction certificate³³. The ombudsman's guidance repeats this: "they should deduct income tax from it at the basic rate before they pay it to you. They should pay it directly to HMRC and give you a tax deduction certificate"³⁴. That certificate is the document you keep for the interest part of any award.

NS&I customers can complain through NS&I's own complaints process, which handles queries about holdings including Savings Certificates, Direct ISA accounts, Direct Saver accounts and Premium Bonds¹⁹. If the complaint is not resolved, it can go to the ombudsman. For anything involving a provider that has failed, the FSCS claims process asks for identity documents such as a passport or valid GB driving licence, with a bank statement or utility bill as examples of extra documents if requested³⁵.