The Personal Savings Allowance Explained: £1,000 Tax-Free Sounds Generous Until You Do the Maths

The Personal Savings Allowance gives you a tax-free chunk of savings interest each year. The size depends on your Income Tax band:

• Basic-rate taxpayer (income £12,571–£50,270): £1,000 tax-free interest
• Higher-rate taxpayer (income £50,271–£125,140): £500 tax-free interest
• Additional-rate taxpayer (income above £125,140): £0 — no allowance at all

The PSA covers interest from bank accounts, building society accounts, credit union accounts, peer-to-peer lending, and government bonds. It does not cover interest earned inside ISAs(https://www.gov.uk/individual-savings-accounts) — that's already tax-free and sits outside the PSA entirely.

Critically, the PSA thresholds haven't changed since 2016. They weren't designed for a world where easy access savings accounts pay 4-5%. The allowance is frozen until at least 2028, meaning more savers breach it every year rates remain high.

Here's where it gets real. At current best rates, the PSA runs out faster than you'd expect.

At 4.68% — the current best easy access rate — a basic-rate taxpayer exceeds their PSA with just £21,368. Every pound of interest above £1,000 is taxed at 20%. On £30,000 in savings, you'd earn £1,404 interest, of which £404 is taxable — costing you £81 in tax.

Higher-rate taxpayers face it worse. At £500 PSA and 40% tax, £30,000 in savings generates £1,404 interest, of which £904 is taxable — £362 in tax. That's a significant chunk of your returns.

Additional-rate taxpayers pay 45% on every penny of savings interest from the first pound. On £50,000 at 4.68%, that's £1,053 in tax.

These numbers assume a single savings account. In practice, many savers spread money across several banks for FSCS protection (£85,000 per institution) or to chase the best rates. All interest from all non-ISA accounts is aggregated for PSA purposes — there's no hiding from it by splitting across providers.

HMRC receives automatic reports from banks and building societies detailing all interest paid. If you exceed your PSA, your tax code is adjusted the following year — or you receive a Simple Assessment letter. Many savers are caught unaware when their January tax code drops because of savings interest they earned the previous April.

The PSA doesn't work alone. Three separate tax reliefs can shelter your savings interest, and they stack:

1. Personal Allowance (£12,570): If your total income (wages, pension, savings interest) is below £12,570, all your savings interest is tax-free regardless of PSA limits. This mainly helps retirees living on modest pensions and part-time workers.

2. Starting rate for savings (up to £5,000): If your non-savings income is below £17,570, you get a starting rate band for savings of up to £5,000. Every £1 of income above the Personal Allowance reduces this by £1. A pensioner earning £14,000 would have a starting rate band of £3,570, plus their £1,000 PSA — totalling £4,570 of tax-free interest.

3. Personal Savings Allowance (£1,000/£500/£0): This sits on top of the other two.

For a basic-rate taxpayer earning £30,000 from employment, the practical tax-free interest is £1,000 (PSA only — the starting rate is fully used by employment income). For a pensioner on £13,000, the combined tax-free interest could be £5,570.

The interaction between these allowances catches many people out. A key rule: the starting rate for savings is separate from the PSA, and both sit on top of the Personal Allowance. But they apply in order — Personal Allowance first, then starting rate, then PSA. You cannot choose which to use first.

For retirees in particular, the combined effect is powerful. A pensioner with state pension of £11,500 (the full new state pension is £11,502.40 per year) and no other income has their entire Personal Allowance unused by savings income. Combined with the starting rate and PSA, they could earn over £6,000 in savings interest before paying any tax — enough to hold over £128,000 in savings accounts at current rates without a tax bill.

Cash ISA interest sits completely outside the PSA. You could earn £20,000 of interest inside a Cash ISA and it wouldn't affect your PSA threshold or your tax bill at all.

This makes the Cash ISA(https://www.gov.uk/individual-savings-accounts) the single most powerful tool for sheltering savings interest from tax — especially for higher and additional-rate taxpayers.

The maths for a higher-rate taxpayer with £40,000 in savings:

Without ISA: £40,000 × 4.68% = £1,872 interest. PSA covers £500. Tax on £1,372 at 40% = £549 tax. Net return: £1,323.

With ISA split: £20,000 in Cash ISA (4.68% tax-free) + £20,000 in savings account (4.68%). ISA earns £936 tax-free. Regular account earns £936, of which £500 is covered by PSA. Tax on £436 at 40% = £174. Net return: £1,698.

Using the ISA saves this taxpayer £375 per year. Over five years of compounding, the difference grows to over £2,000. For additional-rate taxpayers, the saving is even larger because they have zero PSA.

The argument that Cash ISAs are pointless because of the PSA was valid in 2016 when rates were 1%. It isn't valid now.

The compounding effect over multiple tax years makes the ISA even more valuable. ISA interest rolls up tax-free year after year — there's no annual reset, no allowance to breach. A higher-rate taxpayer who's been maxing their Cash ISA for five years at an average of 4% has accumulated roughly £108,000 in tax-free savings, generating over £4,300 of completely tax-free interest annually. Outside an ISA, the same pot would cost them £1,520 in tax each year.

For comparison, putting the same money into Premium Bonds at the current 3. See <a href="/posts/savings-guide-premium-bonds-nsi-rates-202526-how-they-work-current-returns-and-whether-theyre-worth-it">Premium Bonds are already tax-free</a> for more details.30% expected rate would generate £3,564 — tax-free, but £736 less than the Cash ISA. The ISA wins on both return and certainty.

According to HMRC rules, you have until 5 April 2026 to use your 2025/26 ISA allowance. Here's the action plan:

If you're a basic-rate taxpayer with under £20,000 in savings: Your PSA probably covers all your interest. A Cash ISA is still worth opening — it protects you if rates rise further or your income increases, pushing you into the higher-rate band.

If you're a higher-rate taxpayer: Max your Cash ISA immediately. Every pound inside the ISA wrapper is earning 4.68% completely tax-free, compared to an effective rate of 2.81% after 40% tax in a regular account. The best easy access Cash ISAs don't require any lock-in.

If you're an additional-rate taxpayer: The Cash ISA is non-negotiable. Your effective savings rate outside an ISA is 2.57% after 45% tax. Inside the ISA, it's the full 4.68%. Max the ISA, then put excess savings into NS&I Premium Bonds (3.30% expected, tax-free, up to £50,000).

If you're a couple: You each get a £20,000 ISA allowance and separate PSAs. A couple can shelter £40,000 in Cash ISAs plus up to £2,000 (or £1,000) in PSA-covered interest. Splitting savings between partners to use both allowances is the simplest tax planning most households never do.

This article is for informational purposes only and does not constitute financial advice. You should seek independent financial advice before making any investment decisions.