If you work as a freelance locum GP, you have probably noticed that your NHS pension contributions are not worked out on your full session fee. They are worked out on 90% of it.
That 10% gap is not a mistake, and it is not the practice short-changing you. It is a deliberate feature of how the NHS Pension Scheme treats freelance GP locum income, and it has a knock-on effect on both your pension and your tax return.
This guide explains why only 90% of your locum fee is pensionable, how the forms A and B process works, the strict 10-week deadline that catches a lot of locums out, and how the rule sits alongside the rest of your self-employed tax position.
It is written for freelance GP locums who invoice practices directly. If you would rather hand the whole thing over, that is what we do for locum doctors.
What does the 90% pensionable rule mean for locum GPs?
When you pension freelance GP locum work, the NHS Pension Scheme treats only 90% of your gross locum fee as pensionable pay. The other 10% is treated as a notional allowance for your practice expenses, so you pay both your employee tiered contribution and the employer contribution on the 90% figure, not the full invoice.
Why is only 90% of a locum GP fee pensionable?
When you invoice a practice for a locum session, your fee is meant to cover more than your time. It also covers your costs of being a freelance practitioner: your indemnity, your professional subscriptions, your travel, your admin, and so on.
The NHS Pension Scheme recognises this by treating 10% of your gross locum fee as a flat allowance for those expenses. That 10% is not pensionable. Only the remaining 90% counts as your pensionable pay.
So if you raise an invoice for a day's locum work, you do not pension the whole invoice. You pension 90% of it. The BMA puts it plainly: you pay the appropriate percentage against 90% of your gross locum earnings, because the remaining 10% represents expenses that are not pensionable in the scheme.
This is specific to freelance GP locum work pensioned through forms A and B. It is not a general rule that applies to salaried GPs, whose pensionable pay is worked out differently.
How do forms A and B actually work?
Pensioning freelance locum work runs on two forms, and they do different jobs.
- Form A is the per-engagement record. You complete one each time you do pensionable locum work, and the practice certifies that the work was carried out. It captures your fee and the 90% pensionable figure.
- Form B is the monthly summary you send with your payment. It totals your pensionable pay for the period and generates the reference that ties your form A entries to the money you actually pay across.
You pay both the employee and the employer contributions yourself, then claim them back into your own pension record. As a freelance locum you must pay those contributions to NHS England / Primary Care Support England (PCSE) in England, or to your Local Health Board, no later than the seventh day of the month following the month you received payment.
In England the forms go to PCSE. The mechanics differ slightly across the UK, so if you work in Wales, Scotland or Northern Ireland, check the process with the relevant body before you assume the England route applies.
What is the 10-week deadline and why does it matter?
This is the single rule that costs locums pension most often.
You cannot pension a period of freelance GP locum work that ended more than 10 weeks ago. PCSE is explicit that there are no exceptions to this, not even for sickness. Miss the window and that work simply cannot go into your NHS pension, no matter how willing you are to pay the contributions.
The clock runs from the date the work ended. If you worked Monday, Tuesday and Wednesday at one practice, you have 10 weeks from the Wednesday to claim scheme membership for all three days.
In practice, the safe habit is to raise your form A as soon as a session is done and your form B promptly each month, rather than letting invoices and forms pile up. A backlog is how locums quietly lose pensionable years.
How are your contributions calculated on the 90%?
Two contributions come out of the 90% pensionable figure: your employee tiered contribution and the employer contribution.
Your employee contribution is tiered. The NHS Pension Scheme sets several earnings bands, each with its own percentage, and the band you sit in depends on your expected total GP income for the year. As a locum you are responsible for picking the correct tier and applying it to your pensionable pay. These tier rates and the band thresholds are set by the NHS Business Services Authority (NHSBSA) and are reviewed periodically, so check the current member tiers on the NHSBSA member hub before you calculate, rather than relying on a figure from a previous year.
The employer contribution in England and Wales is applied to the same 90% pensionable amount. The portion you pay across as the employer element is currently 14.38% of the pensionable pay, with the rest of the full employer rate met centrally.
The point to hold on to is that both contributions bite on 90%, never on the full fee. Get the 90% wrong and every percentage downstream is wrong too.
Illustrative example: a locum session and the 90% rule
Illustrative example. Suppose Dr Anand does a day's freelance locum session and invoices the practice 600 for it.
| Step | Figure |
|---|---|
| Gross locum fee invoiced | £600.00 |
| Less 10% non-pensionable expenses allowance | £60.00 |
| Pensionable pay (90% of the fee) | £540.00 |
His contributions are then worked out on the 540 pensionable figure, not the 600 invoice:
- His employee tiered contribution applies to the 540, at whatever tier his expected annual GP income puts him in for 2026/27.
- The employer element of 14.38% applies to the same 540, which is £77.65 (£540 x 14.38% = £77.65).
The exact employee figure depends on his tier, which is why we have not stated a single percentage here: locums sit in different bands, and the band rates are set by NHSBSA. What does not change is the base. Every contribution starts from £540, the 90% figure, and Dr Anand has 10 weeks from the day of the session to get it pensioned.
These figures are illustrative. Your own position depends on your fee, your tier and your total GP income for the year.
How does the 90% rule affect your tax return?
This is where locums often conflate two separate things. The 90% pensionable rule is an NHS pension mechanic. It is not a tax deduction, and it does not decide what you can claim as expenses on your Self Assessment return.
For tax, your full locum income is taxable as self-employed profit, and you deduct your actual allowable business expenses, your indemnity, subscriptions, mileage and so on, not a flat 10%. The 10% in the pension rule is a notional allowance inside the pension scheme only.
Your employee NHS pension contributions do get tax relief, but that is handled through your Self Assessment, separately from the 90% calculation. And because you are self-employed, you also pay Class 4 National Insurance on your profits, at 6% between the Lower and Upper Profits Limits and 2% above, for 2026/27.
If you drive between practices, your travel is a real, deductible business cost. You can work it out using HMRC's approved mileage rates of 45p per mile for the first 10,000 business miles in the year and 25p per mile after that, and our mileage calculator does the sums for you. None of that interacts with the pension scheme's 90% figure. They are two different accounts: one is your NHS pension, the other is your tax computation.
What about type 2 and GP SOLO work?
Not all of a locum's work is pensioned through forms A and B.
If you take on out-of-hours, GP-led commissioned services or certain other roles, that work is often pensioned through a GP SOLO form by the organisation paying you, rather than through your own forms A and B.
And if you work for more than six months at a single practice, you can choose to be treated as a type 2 medical practitioner going forward. The practice then pays both the employer and employee contributions directly, as if you were a salaried GP, instead of you running forms A and B for that engagement.
Anyone who has had type 2 pensionable income in a year, including salaried and SOLO work, generally has to complete a type 2 self-assessment form after the year end so that NHSBSA can certify the pensionable pay. This is a pension form, separate from your HMRC Self Assessment tax return, even though the names sound alike. Keeping the two straight, and filing both on time, is exactly the sort of thing we handle for locum and sessional doctors.
Want your locum pension forms and your tax return joined up and filed on time? Book a free call with a Zmartly accountant and we will review where you stand.
Frequently asked questions
Why is only 90% of my locum GP fee pensionable?
The NHS Pension Scheme treats 10% of your gross freelance locum fee as a notional allowance for your practice expenses, so only the remaining 90% counts as pensionable pay. Your employee and employer contributions are both calculated on that 90% figure, not on the full invoice.
Does the 90% rule mean I can only claim 10% of my expenses on my tax return?
No. The 10% is a pension scheme mechanic, not a tax rule. For Self Assessment you deduct your actual allowable business expenses, such as indemnity, subscriptions and mileage, against your full locum income. The two are completely separate calculations.
How long do I have to pension my locum work?
You cannot pension freelance GP locum work that ended more than 10 weeks ago, and PCSE applies this with no exceptions, including for sickness. The 10 weeks run from the date the work ended, so raise your forms promptly.
What employee contribution rate do I pay as a locum GP?
Your employee contribution is tiered, with the percentage depending on your expected total GP income for the year. The tier rates and band thresholds are set by NHSBSA and reviewed periodically, so check the current member contribution tiers on the NHSBSA member hub before you calculate, rather than using a rate from an earlier year.
When do I have to become a type 2 medical practitioner?
If you work more than six months at a single practice, you can choose to be treated as a type 2 medical practitioner prospectively, in which case the practice pays both the employer and employee contributions directly as if you were salaried, rather than you using forms A and B for that engagement.
