Gilts in an ISA or SIPP

The gilt is the same instrument whichever wrapper holds it, but the wrapper decides how its coupons are taxed — and for gilts, whose gains are already tax-exempt, the shelter that matters is income tax.

One gilt, two wrappers

A gilt does not change when it is held inside an ISA or a SIPP: the same clean price, the same coupon, the same £100 at maturity. What changes is the tax treatment of the income it pays and, in the pension's case, of the money when it comes out. For a UK-resident individual the wrapper is the decision, not the gilt, so reading the two together is what makes a holding's return after tax visible.

That is why the question is not which gilt suits a wrapper but how a wrapper changes what a given gilt pays. The gilt's own figures stay the same; the wrapper sits around them.

What an ISA shelters

Income and gains inside an Individual Savings Account are free of UK income tax and capital gains tax. Coupons on gilts held in an ISA are therefore paid without a tax deduction and do not count towards your taxable savings income. Checked against GOV.UK, the ISA allowance for the 2025/26 tax year is £20,000, and gilts count as qualifying investments held in the account.

For a gilt, the shelter an ISA gives on income is the part that matters, because the coupons would otherwise be savings income to report. The wrapper turns taxable coupon income into income that does not touch a return.

What a SIPP shelters

A Self-Invested Personal Pension shelters its investments from UK income tax and capital gains tax while they are held, and gilts sit within that in the same way. The difference from an ISA is on the way out: money drawn from a pension is taxed as income, subject to the pension rules and any tax-free element, so the shelter is a deferral rather than a blanket exemption. Checked against GOV.UK for the 2025/26 tax year, the pension rules set how and when that income is taxed.

So both wrappers shelter the coupons while the gilt is held; they differ in what happens when the money is taken out. That difference is the whole of the choice between them for a gilt.

Gilts are already exempt from capital gains tax

There is a quirk that changes how much the wrapper is doing. Disposals of gilts are exempt from capital gains tax for UK-resident individuals, whether or not they sit in a wrapper — so the CGT shelter an ISA or a SIPP offers adds nothing on the gains side for a gilt. The shelter that matters for a gilt is income tax on its coupons, which is where the wrapper earns its place.

That is worth knowing before choosing a wrapper for its gains treatment alone: for gilts there is no gain to shelter from CGT in the first place. The case for a wrapper rests on the income.

The practical effect is to shift where a wrapper earns its keep. For an equity a wrapper shelters both income and gains; for a gilt it shelters only the income, because there is no gain to shelter. A reader comparing wrappers for a gilt holding is really comparing how each treats its coupons.

The taxable and sheltered split

Because interest inside an ISA or a SIPP is not taxable, a reader holding gilts in both a taxable account and a wrapper needs the two kept apart. GiltIQ's taxable income report sums the coupons and accrued interest of the portfolios you scope it to, per UK tax year; wrapped holdings kept in their own portfolios can be left out of that scope, so the report shows the taxable income and the sheltered income as separate figures rather than one blended total.

On the taxable side, the net yield and net income columns on the gilt lists apply income tax at a chosen band, so the after-tax figure for a taxable holding can be read directly. Read together, the split and the columns answer the two halves of the question: what the taxable holding nets after tax, and what the wrapper leaves untouched.

A gilt can be read pre-tax and post-tax, and the two figures answer different questions. The gross yield is the return on the investment before the wrapper or the tax band; the net yield and net income columns apply a chosen tax rate to show what a taxable holding keeps. Held in a wrapper, the coupons are sheltered; held in a taxable account, the taxable portion is what the report and the net columns describe.

Reading both together is what makes a holding's after-tax return visible. The wrapper and the tax band are inputs a reader sets; the gilt's own figures — clean price, accrued interest, dirty price — do not change with either. The site's part is to show the division clearly, not to decide which wrapper a holding belongs in.

Wrapper by wrapper

The table sets how a gilt's coupons and gains are treated in each of the three places a UK-resident individual might hold one. The rules are for the 2025/26 tax year and come from GOV.UK and HMRC.

Background, not advice

This article explains how the tax treatment of gilt income differs between a taxable account, an ISA and a SIPP; it is general background, not investment, tax or legal advice for any reader's circumstances. The allowances, the ISA limit and the pension rules stated here are for the 2025/26 UK tax year and come from GOV.UK and HMRC; they change from year to year and should be checked against the primary source. The post-tax yield page shows the after-tax figures per band, and the report is a calculation aid, not a tax return.