Your Savings Are Earning More — and HMRC May Want a Slice

For years, savings interest was so low that most people never had to think about tax on it. Now that easy-access accounts and fixed bonds can pay a genuinely useful rate, interest has become income again. Not huge income, necessarily, but enough to matter if you are a higher-rate taxpayer with a £500 Personal Savings Allowance.

The good news is that this is not a complicated tax problem. It is mostly a paperwork-and-arithmetic problem. Spend twenty minutes with your statements, work out what you have actually been paid in interest this tax year, and you can see whether HMRC is likely to want a slice.

First, the allowance rule in plain English

The Personal Savings Allowance is the amount of savings interest you can receive before tax is due. For basic-rate taxpayers, it is £1,000. For higher-rate taxpayers, it is £500. For additional-rate taxpayers, it is £0.

That last point catches people out. If you pay additional-rate tax, there is no tax-free savings interest allowance at all. If you are a higher-rate taxpayer, £500 sounds generous until you remember that it is not a £500 tax rebate. It is a £500 slice of interest that escapes tax. Interest above that is taxed at your marginal rate.

So if you are a higher-rate taxpayer and you earn £600 in savings interest outside an ISA, £100 of it is taxable. At 40%, that is £40 of tax. Not dramatic, but real. If you have a larger pot, or a fixed bond that pays a lump of interest at maturity, the numbers can creep up quickly.

The statement trawl: a twenty-minute job

Start with the current tax year, which runs from 6 April 2026 to 5 April 2027. You are looking for interest credited to savings accounts, not the balance sitting in them. Check easy-access accounts, fixed-rate bonds, current accounts that pay interest, and any regular savers. If a joint account pays interest, your share is usually half unless the actual ownership split is different.

Leave out interest inside a cash ISA, because that is already sheltered. Premium Bond prizes are also not taxable interest. Everything else outside an ISA is worth adding up.

A simple way to do it is to make a list:

• Account name
• Interest credited between 6 April 2026 and today
• Whether it is inside or outside an ISA

Then add the non-ISA interest. If your bank pays interest monthly, this is straightforward. If a fixed bond pays all the interest at maturity, you need to know whether that payment has landed in this tax year or is still to come. If you are unsure, check the account terms or ask the provider.

When HMRC may already know

Banks and building societies report savings interest to HMRC. That does not mean every tax code is instantly correct, but it does mean you should not assume HMRC is completely in the dark. If you are employed or receive a pension and you owe a small amount of tax on savings interest, HMRC may collect it by adjusting your tax code. If you complete a Self Assessment return, you are expected to declare the interest there.

This is why the statement trawl matters. You are not trying to beat HMRC to the post. You are trying to avoid a surprise. If your interest is close to your allowance, or already over it, knowing now gives you time to decide what to do with the rest of the tax year.

The ISA question: worth it or not?

Moving money into a cash ISA now does not erase interest you have already earned outside an ISA this tax year. That interest still counts. What an ISA can do is shelter future interest, so you stop adding to the taxable total.

Whether it is worth it depends on the rates. Compare the taxable account rate with the ISA rate after tax. Suppose a higher-rate taxpayer has already used the £500 allowance and has £10,000 earning 4% outside an ISA. That is £400 of interest. Taxed at 40%, the tax is £160, leaving £240. The effective return is 2.4%.

If a cash ISA pays 3.8%, the same £10,000 would earn £380 with no tax to pay. That is better. But if the ISA pays only 2.2%, the taxable account still wins after tax. So do not move money on principle alone. Check the actual rates, and check whether your fixed bond has an early-access penalty that would wipe out the gain.

The ISA allowance for 2026/27 is £20,000. If you have not used it yet, you may have plenty of room. Just remember that an ISA shelters interest from this point forward, not the interest already sitting in your current account.

A calm decision path

First, add up your non-ISA interest for the 2026/27 tax year. Second, compare it with your Personal Savings Allowance. Third, estimate the tax on any excess at your marginal rate. Fourth, check whether HMRC is likely to have the figures through bank reporting or your Self Assessment return. Fifth, decide whether moving excess cash into an ISA is worth the rate trade-off.

If your interest is well under the allowance, you can file this away until later in the tax year. If you are close to the limit, keep an eye on the next interest payment. If you are already over it, do not panic. It is usually a modest tax bill, and the fix is often simply to use the ISA wrapper for cash you do not need immediately.

The point is not to treat the £500 allowance as a budget you failed to plan for. It is just a threshold. Once you know where you stand, you can make a deliberate choice about whether to keep earning taxable interest or move the next chunk into shelter.