Does a bond gain reduce my personal allowance?

It can. The full chargeable event gain counts in adjusted net income, so if that pushes you over £100,000 your personal allowance is tapered. Top-slicing relief lowers the tax on the gain but does not restore the abated personal allowance on your actual income.

Why does the calculator show a different personal allowance inside the relief?

Step 4 of top-slicing relief uses a notional income with only one year’s slice of the gain, and recomputes the personal allowance at that lower level. That recomputed allowance is internal to the relief — it isn’t a restoration of your real-income personal allowance.

Does the slice, rather than the full gain, count for the child benefit charge?

No. For adjusted-net-income tests such as the High Income Child Benefit Charge, the full gain counts, not the annual-equivalent slice. The slice is only used inside the top-slicing relief computation.

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Does top-slicing relief reduce adjusted net income?

A relief that lowers the tax bill but not the income figure. Why the full bond gain still abates the personal allowance and counts for the child benefit charge.

4 min read · Last reviewed 16 Jun 2026

No. Top-slicing relief reduces the tax on a chargeable event gain; it does not reduce the gain. The full gain stays in the member's adjusted net income (ANI) — so it still abates the personal allowance over £100,000, and still counts for the High Income Child Benefit Charge. The relief is a tax reducer, not an income deduction.

A reducer, not a deduction

Top-slicing relief is given under ITTOIA 2005 s.535 as a reduction of the individual's income tax liability, applied near the end of the income tax calculation. It is not a deduction taken off income at the start. Adjusted net income (ITA 2007 s.58) is built from total income — and the whole chargeable event gain is part of total income. Nothing in the relief takes it back out.

What the relief touches — and what it doesn’t (IPTM-EX-03 figures)

Chargeable gain: £60,000
In adjusted net income: the full £60,000 (not the £10,000 slice)
Personal-allowance taper (ANI > £100,000): applies on the full gain
Top-slicing relief: reduces the tax on the gain only

This trips people because of a genuinely confusing feature of the relief: inside the five-step computation, at Step 4, the personal allowance is recomputed at a lower notionalincome that uses only the annual-equivalent slice. That recomputed PA can be larger than the member's real-income PA — but it lives entirely within the relief calculation. It is not a restoration of the real personal allowance, and it does not feed back into ANI. The member's actual PA, computed on actual ANI including the full gain, stays abated.

So two things are true at once and don't conflict: the personal allowance is abated on the real income (full gain in ANI), and the relief recomputes a notional PA at the slice level to work out the relief. The full five-step working — both the real and the notional figures — is shown on the top-slicing relief calculator. For why that Step-4 recompute exists and how it changed in 2021, see the IPTM3820 explainer, and for the steps themselves, how to calculate top-slicing relief.

ITTOIA 2005 s.535 (relief as a tax reducer) · ITA 2007 s.58 (adjusted net income) · IPTM3820 (the Step-4 notional recompute)

Common questions

Does top-slicing relief reduce adjusted net income?: No. Top-slicing relief reduces the income tax on a bond gain, not the gain itself. The full chargeable event gain stays in adjusted net income (ITA 2007 s.58), so it still affects the personal-allowance taper and the High Income Child Benefit Charge.
Does a bond gain reduce my personal allowance?: It can. The full chargeable event gain counts in adjusted net income, so if that pushes you over £100,000 your personal allowance is tapered. Top-slicing relief lowers the tax on the gain but does not restore the abated personal allowance on your actual income.
Why does the calculator show a different personal allowance inside the relief?: Step 4 of top-slicing relief uses a notional income with only one year’s slice of the gain, and recomputes the personal allowance at that lower level. That recomputed allowance is internal to the relief — it isn’t a restoration of your real-income personal allowance.
Does the slice, rather than the full gain, count for the child benefit charge?: No. For adjusted-net-income tests such as the High Income Child Benefit Charge, the full gain counts, not the annual-equivalent slice. The slice is only used inside the top-slicing relief computation.

Sources & grounding

Rule basis: ITTOIA 2005 s.535 — top-slicing relief is given as a reduction of the individual’s income tax liability (a tax reducer), not as a deduction from income. ITA 2007 s.58 (adjusted net income) — the full chargeable event gain is part of total income and so of ANI; the relief does not remove it.
Engine reading: CLAUDE.md Cluster K (DO-NOT-FIX) — the PA taper is computed on the member’s actual adjusted net income, which includes the full gain, and stays abated; the Step-4 notional PA recompute inside the relief is internal to the relief, not a restoration of the real-income PA/ANI.
Illustrative figure (the £60,000 gain counts in ANI in full, not the £10,000 slice): the engine’s IPTM-EX-03-OFFSHORE anchor; the point is qualitative.

For planning and illustration purposes only. Verify all inputs against source documents. This explainer does not constitute financial or tax advice.