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Onshore bond tax calculator
Estimate tax on an onshore bond gain after relief and tax credit.
Free, no sign-up. AI never does the maths. The working shown with HMRC manual references, for most tax years back to 2020/21; see the limits.
ParaplanAI calculator illustration
Onshore Bond Tax
Calculator illustration from paraplanai.co.uk/calculators/onshore-bond-tax · Calculator last reviewed 15 Sept 2026. ParaplanAI keeps no record of this illustration.
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. Create the compliance annex, with its working and HMRC references, in the signed-in workflow.
Estimate the tax on an onshore bond gain, including top-slicing relief and the tax credit shown on the certificate. Enter the numbers and choose the chargeable person, then tick anything in the short list that applies.
Free to use, with no sign-up. Your figures stay in this browser unless you choose to share them or send them to your workspace. Calculation methods and checks.
— Understanding the result
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 before it sets the credit against the tax due, and never infers the credit from “onshore” alone. It gives the net additional tax due that this one gain causes; until the certificate is answered it shows the top-slicing relief and holds the net additional tax due back and asks you to answer “Income tax treated as paid?” beside it. For the full relief working see the top-slicing relief calculator, and for which wrapper to choose in future see the wrapper tax comparison. It does not calculate a time-apportioned reduction (TAR). With nothing ticked it assumes none is due (no year of non-UK residence, and no assignment, joint ownership or trust that could give one) and says so beside the figure; tick that box if a reduction may apply and it shows no figure. The bond workbench does not calculate TAR either. UK residence alone does not settle whether TAR is due.
For a 2026/27 gain this calculator gives no figure for an individual where the gain is more than £500,000, the other taxable income is more than £300,000 or the bond has been held for more than 40 complete years, or where “Trust taxed on the settlor” is chosen: for the settlor of a non-charitable trust who is alive and UK resident, choose “An individual” and enter the settlor’s other income. It bands all its income as non-savings and has no field for dividends, relief-at-source pension contributions or Gift Aid. For a 2026/27 onshore gain the top-slicing relief calculator, which takes those separately, has the same limits and also gives no figure where the client has more than £20,000 of other savings income or any dividends, relief-at-source pension contributions or Gift Aid.
— 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
Check for time-apportioned reduction before relying on the 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 no TAR is due: with nothing ticked it assumes that, and says so beside the figure.
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).
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 year's whole income tax, including tax on other income. A basic-rate taxpayer therefore often has no further income tax to pay because of the gain; a higher or additional-rate taxpayer pays only the excess above basic rate, after top-slicing relief. Credit left over after the year’s whole income tax cannot be repaid.
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 of a non-charitable trust are the chargeable persons the gain is charged at the trust rate, apart from the trust’s low-income rules: up to 2023/24 the first £1,000 of the trust’s income, gain included, is charged at the basic rate (ITA 2007 ss.491–492), and from 2024/25 nothing is due where that income is £500 or less, both amounts being lower where the settlor made other settlements (up to 2023/24 any that existed in the year; from 2024/25 only those with income charged at trust rates in the year, even if within their own tax-free amount, with some kinds of trust not counted) (s.24B) — where the certificate says income tax is treated as paid, the deemed 20% basic-rate credit still applies, but none of those reliefs do. On the no-TAR-due basis stated above, and with the certificate confirming that, a £50,000 onshore gain over 10 complete years in 2026/27 is £12,500.00 on trustees against £0.00 for an individual with no other income. The calculator asks who the chargeable person is and shows no figure for your own case until you answer (the worked example on load is an individual's). While the person who created a non-charitable trust (other than a bare trust) is alive and UK resident, the gain is taxed on that settlor as their own income, whether or not they can benefit (s.465(3)), so discretionary gift and discounted gift trusts are normally taxed on the settlor: choose “An individual” in the calculator and enter the settlor’s other income. UK trustees of a non-charitable trust are normally taxed only where the settlor died in an earlier tax year or is not UK resident (s.467; IPTM3230).
ITTOIA 2005 s.535(1) (relief where an individual is liable) · s.465(3) · s.467 · IPTM3230 / IPTM3250
Inputs and scope limits
Some individual cases need additional facts or separate workings. Check the limits below before relying on the relief or tax figures.
- Savings and dividends. The tool treats all the other income you enter as non-savings income, such as salary, pension or rent. It has no field for savings interest or dividends, which change the savings allowances, the starting rate for savings and where the gain sits in the bands. The top-slicing relief calculator takes them separately, though on some onshore gains, including any with dividends in 2022/23 or 2026/27, it cannot yet price the result and says so.
- Pension contributions and Gift Aid. No field for personal pension contributions paid with relief at source, or for Gift Aid: the figures assume there were none. Both extend the basic and higher rate limits for the tax due, and pension contributions extend them inside the relief calculation too. The top-slicing relief calculator takes both, though on some onshore gains, including any with them in 2022/23 or 2026/27, it cannot yet price the result and says so.
- Other gains in the same tax year. The tool works on one gain. Where the client has two or more chargeable event gains in the year, the relief is worked out on all of them together (s.537); the bond workbench does that for onshore gains, offshore gains or both, except in 2026/27, when it can combine offshore gains only.
- Income left out of the relief calculation. A termination payment taxed as employment income under ITEPA 2003 s.403, and lease premiums and similar receipts taxed as UK property business profits, are left out of total income inside the relief calculation but still count for the tax due (s.535(5)). The tool uses the same income for both, so it cannot apply that.
- How the complete years are counted. The tool uses the number of complete years (N) you enter and does not count it. On a later part surrender or assignment N usually runs from the previous such event (s.536(2)). An offshore bond issued before 6 April 2013 still runs from the start of the policy, unless on or after that date it was varied to increase its benefits (exercising a right counts), assigned to the client or into or out of a trust (HMRC IPTM3731 counts both), or used as security for the client’s debt (FA 2013 Sch 8 para 7(2)-(3)); then N runs from the previous event as usual. Where the bond was issued in place of, or under an option in, an earlier policy it is counted from the earliest related policy (s.536(4)). Take N from the certificate.
- Scottish taxpayers. For an individual, choose Yes in the calculator. The gain and top-slicing relief remain available. Net additional tax is shown only where the calculation provides the reviewed evidence needed to confirm it; otherwise it is withheld for a separate Scottish tax calculation. The UK-trustee figure uses trust rates and is not affected.
ITTOIA 2005 s.535(5) · s.536(2) · s.536(4) · s.537 · FA 2004 s.192(4) · ITA 2007 s.414(2) · FA 2013 Sch 8 para 7(2)-(3) · IPTM3820 · IPTM3830 · IPTM3840
— 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
Check 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. It assumes none is due unless you tick the box, and then it shows no figure.
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. Where an onshore gain carries tax treated as paid at the basic rate, it is taxed as the highest part of income, above dividends. Inside the top-slicing relief calculation the gain, and its annual-equivalent slice, is also treated as the highest part of income, above dividends, under that calculation’s own rule (ITTOIA 2005 s.535(4)).
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 net additional tax due
The result is the additional income tax the gain causes this year; it never shows less than nil, and credit left over after the year’s whole income tax cannot be repaid.
— 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
- Net additional tax due after relief and credit
- £19,428.00
Computed live by the same engine the tool above runs, on the assumed 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 usually higher. The gap is often close to the credit amount, because the credit is set against the year’s whole income tax after top-slicing relief, including tax on other income; it is smaller, or nil, only where the credit is more than that tax, because the excess cannot be repaid (ITTOIA 2005 s.530(2)). It can also be smaller or larger where the personal allowance is set against income differently (ITA 2007 s.25(2)) or, with dividends, where the gain sits in a different place in the band order. The calculator shows the extra tax the gain causes and never shows less than nil, so where the onshore credit also covers tax on other income, the onshore figure shows nil and the difference between the onshore and offshore figures is smaller than the real one.
— Frequently asked questions
How is tax on an onshore bond gain calculated?
Assuming 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; credit left over after the year’s whole income tax cannot be repaid.
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. It assumes none is due unless you tick the box, and then it gives no figure. The bond workbench does not calculate TAR either.
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 year’s whole income tax, including tax on other income. A basic-rate taxpayer therefore often has no further income tax to pay because of the gain; 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 gain is charged at the trust rate, apart from the trust’s low-income rules: up to 2023/24 the first £1,000 of the trust’s income, gain included, is charged at the basic rate, and from 2024/25 nothing is due where that income is £500 or less, both amounts being lower where the settlor made other settlements (up to 2023/24 any that existed in the year; from 2024/25 only those with income charged at trust rates in the year, even if within their own tax-free amount, with some kinds of trust not counted), though an onshore bond keeps the deemed 20% basic-rate credit where the certificate says income tax is treated as paid (s.467; s.530; s.531; IPTM3230; ITA 2007 ss.491–492 and s.24B). Trustees of a charitable trust are charged at the basic rate instead (s.467(7)); the calculator does not cover that case. While the person who created a non-charitable trust (other than a bare trust) is alive and UK resident, or in the tax year of their death, the gain is taxed on the settlor as their own income whether or not they can benefit, so discretionary gift and discounted gift trusts are usually taxed on the settlor and the individual treatment, including top-slicing relief, applies (ITTOIA 2005 s.465(3); IPTM3240; IPTM3250). Select the chargeable person in the calculator above: for the living UK-resident settlor of a non-charitable trust, choose “An individual” and enter the settlor’s other income.
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 1 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 usually higher. The gap is often close to the credit amount, because the credit is set against the year’s whole income tax after top-slicing relief, including tax on other income; it is smaller, or nil, only where the credit is more than that tax, because the excess cannot be repaid (ITTOIA 2005 s.530(2)). It can also be smaller or larger where the personal allowance is set against income differently (ITA 2007 s.25(2)) or, with dividends, where the gain sits in a different place in the band order. The calculator shows the extra tax the gain causes and never shows less than nil, so where the onshore credit also covers tax on other income, the onshore figure shows nil and the difference between the onshore and offshore figures is smaller than the real one. TAR can apply to qualifying policies of either type, and neither calculator calculates it.
— Related
- Investment bonds: 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
- Guide: the investment bond 5% withdrawal allowance trap on a bond that lost money
- Guide: where a chargeable event gain goes on the tax return (SA101)
- Guide: onshore vs offshore bonds and how top-slicing relief differs
- Full bond TSR workbench — multiple gains, final-year rule, certificate upload and pre-fill (free account)
