Plenty of dentists reach a point in their career where the NHS pension alone does not feel like enough, or where they simply want more control, and they decide to pay into a SIPP or personal pension on top. The logic seems straightforward: the annual allowance is £60,000, so there must be room to contribute privately up to that figure. For a dentist with meaningful NHS service, that logic is usually wrong, and the gap between what they think they can contribute and what they actually can is where an unexpected tax charge appears.

The reason is aggregation. The £60,000 annual allowance is a single limit covering everything added to your pensions in the tax year. Your NHS pension growth and any private contributions are added together and tested against that one figure. This page explains exactly how to add the two, why high-earning dentists get caught, how the taper and carry forward change the maths, and how to size a SIPP contribution so it fits.

This page owns the two-source addition. It does not re-explain how the allowance itself shrinks for high earners, which is covered on our page about annual allowance tapering for NHS dentists, and it links the general annual allowance guide for the basics. Note that the current standard allowance is £60,000 for 2025/26; older material quoting £40,000 is out of date.

One allowance, two sources

Start with the headline, because everything else follows from it. The £60,000 annual allowance is one limit covering all the pension saving you do in a year. Whatever your NHS pension grows by, plus whatever you pay into a SIPP or personal pension, plus any employer contribution, is added together. That single total is what gets compared to the allowance.

The misconception this page corrects is the idea that the NHS pension and a private pension have separate allowances, so that you can let the NHS pension do its thing and then contribute up to £60,000 privately on top. That is not how it works. There is one allowance, and the two sources share it. If your NHS growth has already used £48,000 of the £60,000, you have £12,000 of room left for everything else, not £60,000.

Where the confusion comes from is understandable. The NHS pension is deducted automatically from your pay, so it feels like a fixed cost you have already dealt with, separate from any decision you make about a SIPP. A SIPP feels like a fresh, voluntary choice with its own headroom. But the annual allowance does not see two pots; it sees one tax year and the total pension saving in it. The automatic NHS deduction and the voluntary SIPP payment are added into the same figure, and that figure is what the £60,000 measures. Treating the NHS pension as "already handled" and the SIPP as having a clean £60,000 to play with is precisely the error that produces a charge.

The NHS side: pension input amount, not contributions

For the NHS defined-benefit scheme, the number that counts is the pension input amount, not the contributions deducted from your pay. The pension input amount is the capitalised increase in the value of your promised pension over the year: broadly, the growth in your annual pension over the year multiplied by a standard factor, then adjusted for inflation. It can be a large number in a year when your pensionable pay rises, because a small increase in a defined-benefit pension represents a large capital value.

We do not re-derive the input-amount formula here; our page on NHS pensionable pay and the general annual allowance guide cover that. The practical point for aggregation is simply that you take the NHS input amount from your pension savings statement and treat it as the NHS contribution to your annual allowance for the year. Because NHSBSA often issues that statement after the tax year has ended, you frequently have to estimate it in advance, which we return to below.

The private side: gross contributions

For a SIPP or personal pension, which is a defined-contribution arrangement, the number that counts is the gross contribution. That is your own payment, plus the basic-rate tax relief the provider adds, plus any employer contribution paid in. So if you pay £8,000 into a SIPP from your own funds, the provider grosses it up to £10,000, and £10,000 is the figure that counts against your annual allowance, not the £8,000 you actually paid.

This grossing-up trips dentists up in both directions. Counting the net figure understates your pension input and can lead you to contribute more than the allowance allows. The fix is simple but easy to forget: always use the gross figure, and remember to include any employer contribution in it. Get the right number in, and the aggregation works; get the net number in, and you have understated your position from the start.

A useful sense-check is that the two pension sources are measured on completely different bases, even though they are added together. The NHS side is a defined-benefit measure: the value of a promise that has grown, calculated by NHSBSA using a standard capitalisation factor. The SIPP side is a defined-contribution measure: the actual money paid in, grossed up for relief. They are not comparable as inputs, which is part of why dentists struggle to combine them intuitively. The annual allowance bridges that by converting both into a single "amount added to your pensions this year" figure, and it is the conversion, not the raw contributions, that you compare to £60,000. Holding that distinction in mind, defined-benefit value on one side, cash contribution on the other, both converted to a common input figure, is what keeps the aggregation honest.

Adding the two: the aggregate test

The core of the page is the addition itself. Take the NHS pension input amount, add the gross SIPP and personal-pension contributions for the same tax year, and the result is your total pension input. Compare that total to £60,000, or to your tapered allowance if the taper applies to you. If the total exceeds the allowance and carry forward does not cover it, the excess is charged at your marginal rate.

Consider a dentist with an NHS pension input amount of £48,000 in 2025/26 who plans a £15,000 gross SIPP contribution, thinking they are comfortably under £60,000. The aggregate is £48,000 plus £15,000, which is £63,000, or £3,000 over the £60,000 allowance. With no carry forward, the £3,000 excess is charged at 40%, a charge of £1,200. The real lesson is in the headroom: the SIPP room was only £12,000, not £15,000. The £15,000 contribution was sized against the wrong number, the full allowance, instead of the room left after NHS growth.

Why high-earning dentists get caught

The aggregation bites hardest on exactly the dentists most likely to want a SIPP: high earners with long service. A dentist with many years of NHS membership can have a pension input amount of £40,000 to £60,000 from NHS growth alone, before a penny goes into anything private, particularly in a year when pensionable pay steps up. At that point even a modest private top-up tips them over the allowance.

The instinctive "I can pay in up to £60,000" is wrong precisely because the NHS has usually already used most of the allowance. The more senior and better-paid the dentist, the smaller the real headroom, which is the opposite of what intuition suggests. This is why the aggregation should be the first calculation a dentist does before opening or topping up a SIPP, not a check they run afterwards.

There is a second reason the NHS input can spike unexpectedly: pay progression. A defined-benefit input amount is driven by how much your promised pension grows over the year, and in a year where your pensionable pay steps up, perhaps because you take on more NHS commitment, become a partner, or your contract value rises, the growth in the promise can be large even though the cash going into the scheme has barely changed. So the very year a dentist feels flush enough to start a SIPP can be the year their NHS input is at its highest, which is exactly the worst time to assume the full allowance is free. The takeaway is not that progression is bad, but that the NHS input amount is lumpy and worth estimating year by year rather than assumed to be stable.

The taper shrinks the shared allowance

For high earners the £60,000 may not even be the starting figure. The taper reduces the allowance toward a £10,000 floor where threshold income exceeds £200,000 and adjusted income exceeds £260,000, cutting the allowance by £1 for every £2 of adjusted income above £260,000. A tapered allowance leaves far less room for any private contribution once NHS growth is counted, and for some dentists the NHS input alone exceeds the tapered allowance, so there is no room for a SIPP at all.

Take a principal with threshold income of £210,000 and adjusted income of £290,000. The £30,000 of adjusted income above the £260,000 floor, halved, reduces the £60,000 allowance by £15,000, to a tapered allowance of £45,000. If their NHS input amount is £42,000, that leaves only £3,000 of room for any SIPP contribution before a charge. A planned £10,000 SIPP top-up would push £7,000 over. The taper can, in other words, shrink the shared allowance below the NHS growth alone, and the SIPP plan has to be sized to whatever sliver remains. The detail of how the taper is calculated lives on our taper page.

The relevant-earnings cap on tax relief: a separate limit

It is worth separating two limits that are easy to conflate. The annual allowance limits the total pension input before a charge applies. A different limit, the relevant-earnings cap, controls how much personal contribution gets tax relief: personal contributions only attract relief up to 100% of your relevant UK earnings, itself capped at the annual allowance.

These are two distinct ceilings a dentist must satisfy at once. A dentist with modest relevant earnings could run into the relief limit even where the annual allowance still has room. A high earner could have ample relevant earnings but no annual allowance room because of the taper or NHS growth. The tax relief on contributions has its own page, dentist pension contributions and tax relief, which is where the relief mechanics belong; the point here is just that clearing the annual allowance is not the same as qualifying for relief, and both have to be met.

One practical wrinkle is that the relevant-earnings test looks at your taxable earnings, not at the headline profit of a practice. For a sole-trader or partnership dentist that is broadly the taxable trading profit. For a dentist drawing salary and dividends from a company, dividends do not count as relevant earnings, so a principal who pays themselves mostly in dividends can find their relief-eligible personal contributions are smaller than they assumed. That is a separate issue from the NHS aggregation, but it bites the same dentists, and it is worth checking both limits in the same exercise rather than assuming that satisfying one satisfies the other. Employer contributions, by contrast, are not constrained by the individual's relevant earnings, which is one reason company contributions can be the better route where personal relief room is tight.

Carry forward across both sources

The main planning lever is carry forward, and it applies across both sources. Unused annual allowance from the previous three tax years (current year's allowance first, then the oldest carried-forward year) can be added to the current year's allowance, and that headroom is shared across NHS and private inputs alike. A dentist with quiet pension years behind them can therefore make a larger SIPP contribution than the current year alone would permit, without a charge.

Return to the dentist with the £63,000 aggregate from earlier. If they have £20,000 of unused allowance carried forward from the previous three years, the £3,000 excess over £60,000 is fully absorbed, so no charge arises, and in fact they could have contributed up to £32,000 to the SIPP before a charge bit. The difference between a £1,200 charge and no charge at all came down to whether they checked carry forward before sizing the contribution. It should always be checked first. The mechanics are set out in our general annual allowance guide.

The money purchase annual allowance trap

One trap removes the carry-forward lifeline for the private side. If you have already flexibly accessed a defined-contribution pot, for example by drawing taxable income from a SIPP while still working, you trigger the money purchase annual allowance of £10,000. From then on, further DC contributions, including SIPP payments, are capped at £10,000 a year, and carry forward is not available for that DC element.

This catches dentists who start drawing a private pension while continuing to work and contribute. They may look at their overall position, see that their NHS-inclusive allowance appears higher, and assume they can pay a larger sum into the SIPP, when in fact the DC contributions are capped at £10,000. If you are drawing benefits from a DC pot while still building one, check whether the money purchase allowance applies before contributing. This interacts with drawing your pension early or in stages, covered in our pages on taking your NHS pension early and partial retirement.

A point that reassures some dentists: taking a tax-free lump sum on its own, or moving a pot into drawdown without yet taking taxable income, does not by itself trigger the money purchase allowance. It is the act of flexibly accessing taxable income from a DC pot that triggers it. Drawing your NHS defined-benefit pension does not trigger it either, because the money purchase allowance is about defined-contribution flexibility, not defined-benefit retirement. So a dentist who takes their NHS pension but leaves a SIPP untouched, or only takes the tax-free element, keeps the normal allowance for further DC saving. The trap is specific, and knowing exactly what springs it stops dentists from either walking into it or over-worrying about it.

Working out the combined position before the tax year ends

The right sequence is the same every year, and the order matters:

  • Estimate the NHS input amount. Use last year's statement and your expected pensionable pay; do not wait for the official statement, which is often late.
  • Gross up the planned SIPP contribution. Add basic-rate relief and any employer contribution to get the gross figure.
  • Add them. NHS input plus gross private contributions equals total pension input.
  • Compare to your allowance. Use the tapered figure if the taper applies.
  • Apply carry forward. Add unused allowance from the prior three years.
  • Size the SIPP to fit. Set the contribution at the room that remains, and do it before paying in.

The discipline is to do all of this before making the contribution. The alternative, contributing first and discovering the charge when the NHS statement finally arrives, is how avoidable charges happen.

If you go over: the charge and how to pay it

If the combined input exceeds your allowance after carry forward, the excess is added to your taxable income and charged at your marginal rate. You can pay it personally, or for the NHS-attributable part you may be able to use NHS Scheme Pays to have the scheme settle it in exchange for a reduced pension. The SIPP-attributable part generally cannot be paid through NHS Scheme Pays, though some DC schemes run their own facility, so a charge produced by combined input may need to be settled through more than one route. Splitting the charge correctly between the NHS and private parts is a point worth getting advice on.

Common errors

The recurring mistakes are easy to list and easy to avoid:

  • Treating the £60,000 as available for private contributions on top of the NHS growth. It is shared, not additional.
  • Using net rather than gross SIPP figures. Always gross up, and include any employer contribution.
  • Ignoring the taper. A high earner's allowance may already be well below £60,000.
  • Forgetting the money purchase allowance. Flexibly accessing a DC pot caps future DC contributions at £10,000.
  • Making the SIPP contribution before checking the NHS statement. Estimate the NHS input first, then size the contribution.

How a specialist dental accountant helps

The aggregation is simple arithmetic once you have the right numbers, but getting the right numbers, especially the NHS input amount before the statement arrives, is where the work is. We have worked with a dentist who was about to make a five-figure SIPP contribution on the assumption that the full £60,000 was theirs to use. The work was to estimate the NHS input amount first, which showed the real headroom was a fraction of what they expected, then to apply carry forward and size the contribution so it fit inside the allowance. The dentist still topped up, but at a figure that avoided a charge rather than triggering one.

If you are planning a SIPP or personal-pension contribution alongside the NHS pension, the right next steps are to estimate your NHS input amount, gross up the planned contribution, add the two, apply any taper and carry forward, and size the contribution before you pay in. If the combined figure does breach the allowance, our pages on the taper and on Scheme Pays cover what comes next.