Fixed-Rate Bond Interest and the Personal Savings Allowance Trap 2026/27

Fixed-rate savings bonds have been popular while rates are decent, but the way they pay interest can create an avoidable tax bill. The culprit is timing: a multi-year bond that pays everything at the end can crash through your Personal Savings Allowance in a single tax year.

The Personal Savings Allowance in 2026/27

The Personal Savings Allowance lets you earn some bank and building society interest tax-free:

• Basic-rate taxpayers: GBP 1,000.
• Higher-rate taxpayers: GBP 500.
• Additional-rate taxpayers: GBP 0.

Interest within your allowance is taxed at 0%. Above it, it is taxed at your marginal rate: 20%, 40% or 45% in England, Wales and Northern Ireland.

Why the timing matters

Interest is generally taxed in the year it is made available to you. A bond that credits interest annually, with access, is usually taxed each year. But many three and five-year bonds pay all the interest at maturity. In that case several years of interest can land in one tax year.

That is fine if the lump still fits within your allowances. It is expensive if it does not, because the excess is taxed at your full marginal rate in a year when, spread out, much of it might have been tax-free.

Worked example

Grace, a higher-rate taxpayer, puts GBP 40,000 into a three-year fixed bond at 4.5% that pays all interest at maturity. Over three years it earns roughly GBP 5,650 of interest, all credited in one tax year.

• Personal Savings Allowance: GBP 500 at 0%.
• Remaining GBP 5,150 taxed at 40% = GBP 2,060.

If instead she had held a bond paying accessible interest each year of about GBP 1,800, she would still exceed her GBP 500 allowance, but the annual excess would be smaller and steadier, and she could pair it with a Cash ISA to shelter part of the pot. The single-year lump is what does the damage, not the total interest.

Planning around the trap

You have several levers, used before you commit the money rather than after:

• Choose bonds that credit accessible interest annually so it is taxed year by year.
• Ladder maturities so that interest from different bonds lands in different tax years.
• Use your Cash ISA allowance, up to GBP 20,000, so that interest on part of the pot is tax-free regardless of timing.
• Check the starting rate for savings: if your non-savings income is low, up to GBP 5,000 of savings interest can be tax-free on top of the Personal Savings Allowance.
• Consider which spouse holds the bond, steering interest towards a lower-rate or non-taxpaying partner.

A note on reporting

If your only untaxed income is savings interest, HMRC often collects any tax due by adjusting your tax code rather than requiring a return, using information banks report. But a large maturity lump can trigger a Self Assessment requirement or a tax-code change, so it pays to anticipate it.

A quick checklist before you lock money away:

• Confirm exactly when the bond pays interest.
• Estimate the interest that will fall in each tax year.
• Compare it against your Personal Savings Allowance and starting rate band.
• Decide how much to keep in a Cash ISA instead.
• Spread maturities if you are building a larger savings pot.

This is general information, not financial advice, and your tax depends on your full income. Check gov.uk guidance on Tax on savings interest and the starting rate for savings, and use the savings calculator at calchub.uk to project your interest before you choose a bond.