For an additional-rate taxpayer there is no personal savings allowance, so the coupon bill is 45 per cent of the whole coupon, and on the same illustrative gilt the coupon keeps £2.20 for every £100 rather than the £3.20 the net income (20%) column shows.
The same gilt at the additional rate
This is the third of three posts working the same gilt through the three income tax bands. The gilt, the nominal and the coupon are identical to the basic-rate and higher-rate posts; only the band changes. An additional-rate taxpayer meets a savings rate of 45 per cent, checked against GOV.UK and HMRC for the 2025/26 tax year, and receives no personal savings allowance at all.
The illustrative gilt pays a 4.00 per cent coupon — £4.00 on every £100 of nominal — quoted at a clean price of 98.50, on a holding of £50,000 nominal, for an annual coupon income of £2,000. None of these is a quote from a real gilt; they are the stated inputs that stay fixed across the three posts.
The inputs do not change from the earlier posts, so the only things that move are the rate and the allowance. Every figure below can be read against the basic-rate and higher-rate posts without adjusting for a different gilt or a different holding.
The bill with no allowance
At 45 per cent the tax on the full £2,000 coupon is £900, and the coupon keeps £1,100. Per £100 of nominal that is a bill of £1.80 and a net of £2.20. Because the personal savings allowance is nil at this band, there is no sheltered slice in front of the rate: the 45 per cent applies to the whole coupon from the first pound.
| Measure | Per £100 nominal | On £50,000 nominal |
| Annual coupon (gross) | £4.00 | £2,000 |
| Personal savings allowance, 2025/26 | £0 | £0 |
| Tax at 45% (no allowance) | £1.80 | £900 |
| Net income at 45% | £2.20 | £1,100 |
The row that changes most from the other two posts is the allowance row: £1,000 at the basic rate, £500 at the higher rate and nothing here. The band move from higher to additional is only five percentage points on the rate, but losing the £500 allowance as well means the taxable coupon rises from £1,500 to the full £2,000 as the rate climbs from 40 to 45 per cent.
The personal savings allowance is nil at the additional rate for the 2025/26 tax year, from GOV.UK and HMRC. A reader at this band therefore has no sheltered slice to set against the coupon: the first pound is taxed at 45 per cent just as the last is, and the whole coupon competes directly with the rate.
Across the three bands
The series can be read in one table. Each row takes the same £4.00 coupon and applies that band's rate before allowances, and lists the personal savings allowance that would sit in front of the rate for the 2025/26 tax year.
| Band | Tax on a £4.00 coupon per £100 | Net per £100 before allowances | Personal savings allowance 2025/26 |
| Basic 20% | £0.80 | £3.20 | £1,000 |
| Higher 40% | £1.60 | £2.40 | £500 |
| Additional 45% | £1.80 | £2.20 | £0 |
The gross coupon never moves; only the rate and the allowance do. The net income (20%) column on the gilt lists describes the third column's basic-rate row, and a reader at a higher band adjusts it up for their own rate and down for their own allowance. That is why a single net figure quoted without its band is not comparable with another.
The gross coupon is the same on every row because it is the same gilt. What the table isolates is the pair of variables a band carries: the rate applied to the coupon and the allowance that sits in front of it. A reader who knows their own band can read their row directly; a reader near a boundary between bands checks which band applies to them for the tax year rather than assuming, because the rate and the allowance both step at the boundary.
Why the jump from the higher rate is more than five points
The additional rate is five percentage points above the higher rate, but the coupon keeps £300 less at this band than at the higher rate — £1,100 against £1,400 — because the £500 allowance disappears as well as the rate rising. Of that £300, £225 is the lost shelter: the £500 slice the higher-rate allowance used to cover now bears 45 per cent. The other £75 is the five-point rate rise applied to the £1,500 that was already taxable at the higher rate.
The rate change is the smaller part of the step. A reader comparing the higher and additional bands does not read the five points as the whole of the difference: the lost allowance carries more of it, just as the smaller allowance carried part of the step from the basic rate to the higher.
Where the two figures sit
The post-tax yield page shows the net income and net redemption yield at a range of constant rates, so the 45 per cent case can be read directly rather than inferred from the 20 per cent column. The conventional gilts list carries the gross coupon and the income per £100 the bill is calculated from.
The two pages together answer what the coupon pays and what it keeps at the additional rate. With no allowance to absorb the first slice, the kept figure at this band is just the coupon less 45 per cent of it.
Background, not advice
This article works the additional-rate tax on a gilt coupon; it is general background, not investment, tax or legal advice for any reader's circumstances, and it is not a substitute for professional tax advice. The 45 per cent rate and the nil personal savings allowance are for the 2025/26 UK tax year and come from GOV.UK and HMRC; the gilt, the nominal and the coupon are illustrative and not a quote from any gilt. GOV.UK and HMRC are the primary sources for a real rate or allowance.