Public sector pension lump sums: how commutation works (with examples)

When you take a public sector pension, you can usually swap some of the annual income for a one-off tax-free lump sum. The jargon for this is commutation, and the rate at which the swap happens is the single most important number to understand: in most public service schemes it is 12 to 1. Give up £1 of annual pension and you get £12 of cash, once and tax-free, but your pension is permanently lower for the rest of your life.

This explains how lump sums work across the main public service schemes, which schemes hand you one automatically, how the maximum is worked out, and what the trade-off actually looks like with real numbers. It describes the mechanics, not what you should choose: whether to take a bigger lump sum or a bigger pension is a personal decision, and one worth taking to impartial guidance.

What commutation is

Commutation is the exchange of part of your annual pension for an immediate lump sum. Public service schemes set the exchange rate, called the commutation factor, by reference to the scheme actuary’s figures. For most of the schemes covered here that factor is 12, meaning you receive £12 of lump sum for each £1 of yearly pension you surrender. The lump sum is paid tax-free, within limits; the pension you keep is taxed as income in the normal way.

The important word is permanent. Commuting is not a loan or an advance. The £1 of pension you give up is gone for good, and because public service pensions are index-linked, you are giving up an income that would otherwise have risen with inflation every year for the rest of your life. That is the heart of the trade-off, and it is why the decision deserves more thought than the headline “tax-free cash” makes it sound.

Automatic lump sums, and schemes without them

Whether you get a lump sum without doing anything depends on which part of which scheme your benefits are in. The broad dividing line is the 2008 reforms.

Older final-salary sections, broadly those you joined before around 2008, often pay an automatic lump sum, classically three times your annual pension, on top of which you can usually commute more if you want to. The NHS 1995 section is the clearest example: it pays a standard lump sum of three times the pension automatically. The Civil Service classic scheme works similarly for pre-2008 members. Sections you joined from 2008 onwards, including the NHS 2008 section and 2015 scheme, and the Civil Service nuvos and alpha schemes, generally pay no automatic lump sum at all. You start with pension only, and create a lump sum by choosing to commute.

How the maximum is calculated

There is a ceiling on how much you can take tax-free. The rule is that the tax-free lump sum cannot exceed 25% of the capital value of your benefits, and there is an overall cap, the Lump Sum Allowance, of £268,275 (the figure inherited from the old lifetime allowance, which was abolished in April 2024). Most public service members come up against the 25% test long before the £268,275 cap.

Schemes turn that 25% rule into a simple multiplier of your pension. In the NHS, the maximum lump sum is about 5.36 times your pension in the 1995 section (where part of the maximum is the automatic three-times lump sum) and about 4.28 times your pension in the 2008 section and 2015 scheme. Other schemes apply the same 25% principle but their exact factor differs a little, so treat the NHS figures as a worked illustration of the method rather than a number to use for, say, the LGPS.

A worked example

Take an NHS 2008 section member with an annual pension of £33,660 before any lump sum.

• Maximum lump sum: £33,660 × 4.28 = £144,060.
• Pension given up to get it: £144,060 ÷ 12 = £12,005 a year.
• Pension you keep: £33,660 − £12,005 = £21,655 a year.

So this member could take £144,060 tax-free, but their annual pension would fall from £33,660 to £21,655 for life. Whether that is a good deal depends entirely on personal circumstances, how long you expect to draw the pension, your tax position, what else you have, and what you would do with the cash. The arithmetic is neutral; the judgement is not, and it is not one this article can make for you.

The 12-year break-even, and its limits

Because the rate is 12 to 1, a tempting back-of-envelope sum is that it takes 12 years of the pension you gave up to add back up to the lump sum you received. In the example above, £12,005 a year for 12 years is roughly £144,060. On that crude basis, someone who draws the pension for much longer than 12 years gives up more in total income than the cash was worth, and someone who draws it for less gets the better of the swap.

It is genuinely useful as a first sniff test, but it is not the whole picture, and it is worth knowing why. The pension you give up is taxable, so each £1 forgone is worth less than £1 in your pocket, which tilts things towards the lump sum. But the pension is also index-linked, so the £12,005 would have grown with inflation over those years, which tilts back the other way. And the lump sum is only worth what you do with it. These are exactly the moving parts a regulated adviser is there to weigh, and why the 12-year rule is a starting point for thinking, not an answer.

How to get your own figures

Your scheme will give you the real numbers, and they are the only ones that count. When you ask for a retirement quote, it will normally show your pension, your automatic lump sum if you have one, the maximum lump sum you could take, and the pension that would remain at that maximum, usually with one or two options in between. Your annual benefit statement and your scheme’s online portal are the starting points, and the scheme guides on this site, for the NHS, Civil Service, Teachers’ and LGPS schemes, set out how each one is built. For free and impartial guidance on the lump-sum decision, MoneyHelper is the government-backed service, and for regulated advice tailored to your circumstances you would speak to a financial adviser authorised by the Financial Conduct Authority.

Common questions

Pension Plain’s take

The number to hold on to is 12 to 1, because it is the same whether you commute a single pound or the maximum, and it frames the whole decision. Giving up index-linked, taxable income for life in exchange for tax-free cash today is sometimes exactly the right move and sometimes not, and the honest answer is that the maths alone does not settle it. The 12-year break-even is a useful sniff test, but it quietly ignores tax and inflation, which pull in opposite directions. What this means in practice is that the lump-sum decision is one of the few places in a public service pension where a conversation with a regulated adviser, or at least free guidance from MoneyHelper, genuinely earns its keep, because the right answer is personal and irreversible.

Fact-checked: 17 June 2026