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Onshore bond tax calculator
The tax on one onshore investment bond's chargeable-event gain — after confirming that no time-apportioned reduction is due — with top-slicing relief and the deemed 20% basic-rate credit.
Free, no sign-up. Runs the same engine and versioned tax-year config as the signed-in suite — the pension and bond calculation workbench UK paraplanners use to produce compliance-annex PDFs. Your calculator figures stay in this browser unless you choose to share or rerun them in the signed-in workbench. How we verify the numbers.
— In short
An onshore bond's chargeable-event gain is added to your income as savings income; top-slicing relief moderates the effect of a multi-year gain landing in one tax year; and where the certificate confirms income tax is treated as paid, a deemed 20% basic-rate credit is set against the tax under ITTOIA 2005 s.530. Some UK-policy cases are excluded by s.531, so this tool requires that exact certificate answer and never infers the credit from “onshore” alone. It gives the tax on this one gain — not the relief figure alone (see the top-slicing relief calculator), nor which wrapper to choose in future (see the wrapper tax comparison). It does not calculate a time-apportioned reduction (TAR), so it releases no final tax or top-slicing figure until you confirm that no TAR is due after checking the relevant residence, beneficial ownership or assignments, security, and trust or estate history. UK residence alone is not enough to make that confirmation.
ParaplanAI calculator illustration
Onshore Bond Tax
Tax year 2026/27 · Last reviewed 20 Jul 2026
Gain, years, income.
Who is taxed on this gain. Top-slicing relief, the personal allowance, the personal savings allowance and the starting rate for savings are available only where an individual is liable on the chargeable event gain (ITTOIA 2005 s.535(1)). Where UK trustees are the chargeable persons the whole gain is charged at the trust rate with none of those reliefs (s.467; IPTM3250 / IPTM3260). Choose the chargeable person below — this tool computes for an individual unless you select otherwise.
From the certificate, or the chargeable-event-gain calculator.
Complete policy years to the event — used to slice the gain.
An individual policyholder — top-slicing relief and the savings allowances apply (ITTOIA 2005 s.535(1)).
Drives the bands, allowances and rates — versioned per-year config. A certificate for an earlier year must be priced on that year's thresholds.
Must fall inside 2026/27 (6 April 2026 to 5 April 2027). Gains arising on or after 6 April 2021 have the personal savings allowance and starting-rate band recalculated at the slice (IPTM3820).
Salary, pension, self-employment, rental — gross, before the personal allowance. Excludes the bond gain.
Don't have the gain yet? Work it out on the chargeable event gain calculator and bring the figure here. Uses the 2026/27 versioned tax-year config. This quick tool bands all entered income as non-savings — if the taxpayer also has savings interest or dividends, use the top-slicing relief calculator, which takes the three income types separately.
For planning and illustration purposes only. Verify all inputs against source documents. This tool does not constitute financial or tax advice.
Print this quick illustration now. Signed-in users can add a client or file reference before saving it as a PDF — the branded compliance annex, with the full working and HMRC references on every page, comes from the signed-in workflow.
Keep the working
Save this as a branded compliance annex PDF.
A free account saves this calculation to a client record and renders the annex — 3 a month, no card.
More than one gain in the same tax year, or a certificate to reconcile? The bond workbench handles multiple gains, the final-year rule and certificate reconciliation. Neither surface calculates TAR.
— How it's calculated
The gain is taxed as savings income
A chargeable-event gain on an onshore bond is not a capital gain — it is treated as savings income of the year the event falls in. Where s.530 tax is treated as paid, s.465A and ITA 2007 s.1012 make it the highest part of income, above dividends, in the real main calculation. It is added to the member's income in full; the personal savings allowance and the starting rate for savings can apply to it, and the gain can itself taper the personal allowance once adjusted net income passes £100,000.
IPTM3810 (onshore gains) · ITTOIA 2005 s.465–465B
Resolve time-apportioned reduction before the final tax figure
TAR can apply to qualifying onshore as well as offshore policies. Whether it is due can depend on relevant residence, beneficial ownership or assignments, rights held as security, and trust or estate history, so UK residence throughout the policy term alone does not settle the question. This calculator does not calculate TAR and is limited to gains for which you can confirm, after those checks, that no TAR is due.
Top-slicing relief
A gain that built up over several years is charged in a single year, which can push it through the higher or additional-rate threshold. Top-slicing relief compares the tax on the whole gain with the tax on the annual-equivalent “slice” (the gain divided by the complete policy years) scaled back up — reducing the liability where the slice falls in a lower band than the whole gain. The personal savings allowance and starting-rate band are recalculated at the notional slice income for gains from 6 April 2021 (the post-2021/22 IPTM3820 recalculation).
ITTOIA 2005 s.535–537 · IPTM3820 · HMRC Agent Update 83 (2021)
The onshore 20% basic-rate credit
An onshore bond's fund suffers tax internally, so the holder is treated as having already paid basic-rate tax on the gain. A deemed 20% basic-rate credit — restricted to the gain less any personal allowance set against it — is set against the tax on the gain. A basic-rate taxpayer therefore often has no further income tax to pay; a higher or additional-rate taxpayer pays only the excess above basic rate, after top-slicing relief. The credit cannot create a repayment.
Who is taxed on the gain — individual or trustees
Top-slicing relief is available only where an individual is liable on the chargeable event gain, and the personal allowance, personal savings allowance and starting rate for savings are individual reliefs too. Where UK trustees are the chargeable persons the whole gain is charged at the trust rate — the deemed 20% basic-rate credit still applies, but none of those reliefs do. On the no-TAR-due basis stated above, a £50,000 onshore gain over 10 complete years is £12,500.00 on trustees against £0.00 for an individual with no other income. The calculator computes for an individual policyholder unless you select UK trustees as the chargeable person; where the trust is settlor-interested the gain is instead assessed on the settlor as their own income.
ITTOIA 2005 s.535(1) (relief where an individual is liable) · s.467 · IPTM3250 / IPTM3260
— How to calculate the tax on an onshore investment bond gain
Step 1
Take the chargeable event gain
Start from the chargeable event gain on the bond — from the provider certificate, or the chargeable event gain calculator.
Step 2
Confirm that no TAR is due
Check the relevant residence, beneficial ownership or assignments, security, and trust or estate history. The calculator does not calculate TAR and produces no final tax or top-slicing figure unless you can confirm that no TAR is due.
Step 3
Add the gain to income as savings income
Add the full gain to the member’s other taxable income for the year; it is savings income, sitting above other income but below dividends.
Step 4
Apply top-slicing relief
Slice the gain by the number of complete policy years, tax the slice at the notional income level, scale back up, and take the relief against the tax on the whole gain.
Step 5
Set the 20% basic-rate credit against the tax
Deduct the deemed 20% basic-rate credit (restricted to the gain less any personal allowance set against it) — a basic-rate taxpayer often has no further tax to pay.
Step 6
Read the tax on the gain
The result is the additional income tax the gain causes this year; the credit cannot reduce it below nil or create a repayment.
— Worked example
- Chargeable event gain (no TAR due)
- £80,000.00
- Annual equivalent / slice (gain ÷ 8)
- £10,000.00
- Top-slicing relief
- £2,343.00
- Deemed 20% basic-rate credit (onshore)
- £16,000.00
- Tax on this gain, after relief and credit
- £19,428.00
Computed live by the same engine the tool above runs, on the confirmed basis that no time-apportioned reduction (TAR) is due; the engine has not calculated or applied TAR. TAR can apply to qualifying onshore as well as offshore policies, and UK residence alone does not settle whether it is due. The identical offshore case has no basic-rate credit against its real liability (ITTOIA 2005 s.531(1) keeps the credit inside the top-slicing relief calculation only, so the relief figure is the same), so its tax is higher by the credit amount.
— Frequently asked questions
How is tax on an onshore bond gain calculated?
Once it is confirmed that no time-apportioned reduction (TAR) is due, the chargeable event gain is added to your income as savings income for the year of the event. Top-slicing relief is applied to moderate a multi-year gain landing in one year, then a deemed 20% basic-rate credit is set against the tax for the tax already treated as paid inside the fund. The result is the additional income tax the gain causes; the credit cannot create a repayment.
Can time-apportioned reduction apply to an onshore bond?
Yes, TAR can apply to qualifying onshore as well as offshore policies. UK residence alone does not settle whether it is due: check the relevant residence, beneficial ownership or assignments, security, and trust or estate history. This calculator does not calculate TAR and gives no final tax or top-slicing figure unless you confirm that no TAR is due.
What is the 20% basic-rate credit on an onshore bond?
An onshore bond’s fund is taxed internally, so the holder is treated as having already paid basic-rate tax on the gain. A deemed 20% basic-rate credit — restricted to the gain less any personal allowance set against it (ITTOIA 2005 s.530(3)–(5)) — is set against the tax on the gain. A basic-rate taxpayer often has no further tax to pay; a higher-rate taxpayer pays the excess above basic rate after top-slicing relief.
Do basic-rate taxpayers pay tax on an onshore bond gain?
Often not. Because the deemed 20% basic-rate credit matches the basic-rate liability, a gain that stays within basic rate after being added to income — with top-slicing relief where a multi-year gain would otherwise push into higher rate — frequently leaves no further income tax to pay. A gain large enough to cross into higher or additional rate does produce a charge on the excess.
Is an onshore bond gain a capital gain?
No. A chargeable event gain is charged to income tax as savings income under the chargeable-event regime (ITTOIA 2005 s.461–465), not to capital gains tax. It uses the personal savings allowance and starting rate for savings rather than the CGT annual exempt amount, and it counts towards adjusted net income for the personal-allowance taper.
Does top-slicing relief apply to a bond held in trust?
Not where UK trustees are the persons chargeable on the gain. Top-slicing relief is given only where an individual is liable (ITTOIA 2005 s.535(1)), and trustees also get no personal allowance, no personal savings allowance and no starting rate for savings — the whole gain is charged at the trust rate, though an onshore bond keeps the deemed 20% basic-rate credit (s.467; s.530; IPTM3250). Where the trust is settlor-interested and the settlor is the chargeable person, the gain is assessed on the settlor as their own income and the individual treatment, including top-slicing relief, applies (IPTM3260). Select the chargeable person in the calculator above.
Can I work out the tax on a gain from an earlier tax year?
Yes — select the tax year the chargeable event falls in and the date of the event. The gain is taxed in the year the event arises, on that year’s thresholds: FA 2023 moved the additional-rate threshold from £150,000 to £125,140 from 2023-24, so pricing an earlier certificate on current thresholds gives the wrong answer. The event date also settles the top-slicing question directly: gains arising on or after 6 April 2021 have the personal savings allowance and starting-rate band recalculated at the notional slice (IPTM3820), while earlier gains carry the Step 3 figures unchanged.
What is the difference between onshore and offshore bond tax?
Once any TAR question has been resolved, the gain and the top-slicing relief come out the same for both — ITTOIA 2005 s.531(1) applies the deemed basic-rate credit to offshore gains too, but only for the purpose of calculating relief under s.535. The difference is the real liability: an onshore bond keeps the credit against it for tax paid inside the fund, while an offshore bond rolls up gross and keeps none, so the offshore tax is higher by the credit amount. TAR can apply to qualifying policies of either type, and neither calculator calculates it.
— Related
- Top-slicing relief: the complete guide
- Offshore bond tax calculator — the same gain with no basic-rate credit against the real liability
- Top-slicing relief calculator — the five-step relief working in full
- Chargeable event gain calculator — work out the gain first
- Pension vs ISA vs bond tax comparison — for a future wrapper choice
- Full bond TSR workbench — multiple gains, final-year rule, certificate reconciliation (free account)
— When you're ready
Put this calculation in the client file.
ParaplanAI is the paraplanner's calculation workbench: the same engine as this free tool, plus document extraction, full multi-event workflows, and a branded compliance annex PDF with the step-by-step working and its HMRC references — the file a compliance officer signs.