Most men reading a payslip in their forties do the maths on this year's pension contribution and stop there. They check the £60,000 annual allowance, top up the SIPP or workplace scheme to somewhere near it, and move on. What almost nobody checks is whether they left allowance unused in 2023/24, 2024/25 or 2025/26 — because HMRC lets you carry that unused headroom forward and use it now, in a single tax year, provided you were a member of a registered pension scheme in each of those years and you have the earnings to support the contribution.
That last clause is where most people quietly disqualify themselves without realising it, and it's worth getting straight before you start planning around a number that might not be available to you.
Why the three-year lookback exists in the first place
Carry forward was designed for exactly the situation a lot of higher earners find themselves in: income that spikes in one year — a bonus, a business sale, an inheritance you want to shelter, a year where a SIPP contribution suddenly makes sense — after several years of contributing well below the cap. Rather than losing that unused allowance permanently, HMRC lets you reach back three tax years and pull the unused portion forward into the current one, on top of this year's own £60,000. The rule has existed since 2011 in one form or another, and it survived the 2023 overhaul that raised the standard annual allowance from £40,000 to £60,000 and abolished the Lifetime Allowance the following April. What trips people up is the order HMRC applies. You use the current tax year's allowance first, then carry forward from the oldest of the three eligible years before moving to the more recent ones. If you contributed £15,000 in 2023/24 against a £60,000 allowance, that £45,000 of headroom gets used before you touch anything left over from 2024/25. Get the sequencing wrong on a self-assessment return and HMRC will recalculate it for you anyway — but it's the kind of thing worth having your adviser or accountant confirm on paper before you commit six figures to a single SIPP contribution, not after.
Where the tapered annual allowance changes the numbers
None of this works cleanly if you're a high earner subject to the tapered annual allowance, and this is the point where the maths stops being a spreadsheet exercise and starts being a genuine planning problem. If your threshold income exceeds £200,000 and your adjusted income exceeds £260,000, your annual allowance for that year tapers down by £1 for every £2 over the threshold, to a floor of £10,000. A man earning £350,000 in adjusted income in 2025/26, for instance, wasn't working with a £60,000 allowance that year at all — his real figure would have been closer to £15,000, and that's the number that gets carried forward, not the headline £60,000 everyone quotes. This is where I'd push back on the way most people approach this: don't assume your carry-forward pot is three years of £60,000 just because that's the figure everyone talks about. Pull your adjusted income for each of the three prior years, run the taper calculation properly for each one, and only then add up what's actually available. Get an accountant to run this rather than doing it from memory — the taper interacts with pension contributions themselves in a way that can shift adjusted income downward and change the outcome, and it's not worth guessing on a number this size.
The Money Purchase Annual Allowance trap
If you've already drawn flexibly from a defined contribution pension — taken an uncrystallised funds pension lump sum, gone into flexi-access drawdown and taken an income, or cashed in a small pot beyond the trivial commutation limits — none of this carry-forward planning applies to you in the way it applies to everyone else. The Money Purchase Annual Allowance caps further contributions at £10,000 a year, full stop, with no three-year lookback and no taper relief either way. It was raised from £4,000 to £10,000 in April 2023, which sounds generous until you compare it with the £60,000 standard allowance everyone else is working with.
Men in their late fifties who've already taken some tax-free cash and a bit of income from an old workplace pension, then discover a few years later that they want to make a large SIPP contribution around a business sale, are the group who hit this most often. Check whether you've triggered the MPAA before you build any plan around stacking prior years — it's a five-minute check with your pension provider, and finding out after the fact means an unwelcome tax charge rather than a clean contribution.
A worked example: stacking three years into one contribution
Take a management consultant, 44, no tapering issues, who contributed £12,000 in 2023/24, £18,000 in 2024/25, and £22,000 in 2025/26 against a £60,000 allowance in each of those years. That leaves £48,000, £42,000 and £38,000 unused respectively — £128,000 in total — plus this year's own £60,000, for a theoretical maximum contribution of £188,000 in 2026/27.
Whether he can actually use all of it depends on relevant UK earnings in the current tax year, because tax relief on personal contributions is capped at 100% of relevant earnings (employer contributions aren't restricted this way, which is exactly why a lot of high earners route large one-off contributions through their company rather than personally). If his salary plus bonus for 2026/27 comes to £140,000, that's his ceiling for tax-relievable personal contributions this year regardless of how much carry-forward headroom sits unused — the allowance tells you what HMRC permits, the earnings test tells you what you can actually claim relief on.
Realistically, most men in this position land somewhere between £80,000 and £150,000 once the earnings test bites, still a meaningful figure and still worth the paperwork.
The earnings test nobody reads the small print on
Relevant UK earnings mean employment income, self-employment profits, or certain other earned income — not dividends, not rental income, not capital gains, and not the proceeds of a business sale sitting in your personal account. A director who takes most of their income as dividends for tax efficiency, which is common practice and usually the right call for day-to-day tax planning, can end up with almost no relevant earnings and therefore almost no personal carry-forward capacity, even with £150,000 of unused allowance sitting on paper.
The workaround here is straightforward: have the company make the pension contribution directly as an employer contribution instead of paying it out as salary or dividend and contributing personally. Employer contributions get tested against the wholly-and-exclusively rule for corporation tax purposes rather than the personal earnings test, and a business owner using carry forward this way typically ends up with more flexibility than an equivalent employee working through a workplace scheme, not less.
Which SIPP platform actually handles this cleanly
Not every provider processes a large, backdated carry-forward contribution the same way, and this matters more than the platform comparison tables usually let on. AJ Bell and Interactive Investor both accept a single contribution with a covering letter specifying the tax years being used, and their support teams have handled enough of these to process it without back-and-forth. Hargreaves Lansdown does too, though their forms ask for slightly more detail up front on the earnings position for each carried-forward year. Vanguard's SIPP, by contrast, is built around simple regular and lump-sum contributions and isn't the platform I'd choose for a complex multi-year carry-forward payment — it works, but you'll spend more time on the phone confirming it's gone in correctly.
Before transferring a six-figure sum, ask the provider directly how they want carry-forward contributions documented, and get it in writing. A contribution that HMRC later decides wasn't properly evidenced against relevant earnings and available allowance triggers an annual allowance charge — effectively clawing back the tax relief through your self-assessment bill the following January, at your marginal rate, on the excess.
Where this actually pays off
The men who get real value from carry forward aren't usually the ones with steady six-figure salaries maxing out contributions every year anyway — they're the ones with lumpy income: a bonus year, a business sale, a redundancy payout, a year they finally sold the rental property they'd been meaning to offload. If that describes your last twelve months, check your contribution history for 2023/24 through 2025/26 before the current tax year closes, because unused allowance from 2023/24 falls out of the window entirely once 2027/28 begins. It doesn't roll forward indefinitely, and it doesn't warn you when it's about to expire.