If you work as a self-employed locum pharmacist, your tax is no longer handled for you through payroll. You pick up the shifts, you invoice the pharmacy, and you are responsible for telling HMRC what you earned and paying the tax on it.
That means registering for Self Assessment, keeping proper records, claiming the right expenses, and meeting the filing and payment deadlines. Miss a step and you can end up with penalties or a tax bill bigger than it needed to be.
This guide walks through what locum pharmacists need to know for the 2026/27 tax year: when to register, what you can claim, how your National Insurance works, and what to do about your NHS pension. It is written for community and hospital locums working through their own self-employment rather than an umbrella or PAYE arrangement.
If you would rather hand the whole thing over, that is exactly what we do for locum healthcare professionals.
Do locum pharmacists pay tax through Self Assessment?
Yes. If you are a self-employed locum pharmacist, you report your income and pay your Income Tax and National Insurance through Self Assessment. You must register with HMRC, file a tax return each year, and pay what you owe by the deadline. If a pharmacy puts you on its payroll instead, that work is taxed under PAYE and may not need a return on its own.
When do I need to register for Self Assessment as a locum pharmacist?
The moment you start earning self-employed locum income, you have a registration clock running. You must tell HMRC by 5 October following the end of the tax year in which you started.
So if you took your first self-employed locum shift during 2026/27 (the year that began on 6 April 2026), your deadline to register is 5 October 2027. Leave it later and you risk a failure-to-notify penalty.
Registering as a sole trader signs you up for Self Assessment and gets you a Unique Taxpayer Reference (UTR), which you need to file. Do it early. You cannot file a return without the UTR, and it can take a couple of weeks to arrive.
A few points that catch locum pharmacists out:
- Mixed PAYE and self-employed work. Many locums also hold a salaried position. The salaried role is taxed at source under PAYE, but your locum income still needs reporting through Self Assessment. You declare both on the return so HMRC can see your total income and the correct tax band.
- You report by tax year, not invoice date. Your return covers the year to 5 April. Income belongs to the year you earned it, not necessarily the month you were paid.
- Register even if you think you will owe little. Registration is about the obligation to notify, not the size of the bill.
If you run your locum work through a limited company instead of as a sole trader, the rules are different again, and we cover that route for medical and pharmacy contractors on our limited company accounting service.
What expenses can a locum pharmacist claim?
You only pay Income Tax and National Insurance on your profit, which is your locum income minus the costs you incurred wholly and exclusively to earn it. Claiming the right expenses is the single biggest lever on a locum's tax bill, and the one most people under-use.
For a self-employed locum pharmacist, the costs that usually qualify include:
- Your General Pharmaceutical Council (GPhC) registration fee. This is allowable. The GPhC is on HMRC's List 3 of approved professional bodies, and relief is due to pharmacists and pharmacy technicians under section 343 ITEPA 2003 for entry to or retention on the Register of Pharmacists. You must pay it to practise, so it comes off your profit.
- Professional indemnity insurance and relevant defence or membership subscriptions tied to your work.
- Mandatory training and CPD needed to keep your registration and stay current.
- Travel to temporary workplaces. Mileage between assignments, or to a pharmacy that is not a permanent workplace, is generally allowable. If you use your own car, you can claim the HMRC approved mileage rate of 45p per mile for the first 10,000 business miles in the tax year and 25p per mile after that.
- Stationery, phone and a fair business proportion of home and broadband costs where you do genuine admin from home.
- Accountancy fees for preparing your accounts and return.
Two things to keep clear. First, your everyday commute to a regular, fixed place of work is not allowable, so the travel rules turn on whether a pharmacy is a temporary workplace for you. Second, ordinary clothing is not claimable, even a plain shirt you only wear for shifts. A genuine uniform or protective wear is a different matter.
Keep every receipt and a simple mileage log. HMRC can ask you to evidence what you claimed, and a tidy record is the difference between a quick query and a painful one. Good bookkeeping is the foundation here, and it is something we set up for clients as part of our bookkeeping service.
How does National Insurance work for a self-employed locum pharmacist?
On top of Income Tax, your self-employed locum profit attracts National Insurance. For 2026/27 there are two classes that matter.
Class 4 is the main one. You pay it on your profits:
| Class 4 National Insurance (2026/27) | Profit band | Rate |
|---|---|---|
| Main rate | £12,570 to £50,270 | 6% |
| Additional rate | Above £50,270 | 2% |
Class 2 no longer works as a flat weekly charge. From 6 April 2024, self-employed people with profits at or above the Small Profits Threshold (£7,105 for 2026/27) are treated as having paid Class 2, so your National Insurance record and entitlement to the State Pension are protected without a separate payment. If your profits are below that threshold and you want to protect your record, you can pay Class 2 voluntarily at £3.65 per week for 2026/27.
Class 4 is collected through Self Assessment alongside your Income Tax, so there is nothing separate to pay. You can sense-check the numbers with our self-employed tax calculator before your bill lands.
What about my NHS pension as a locum?
This is where pharmacists differ from GP locums, so be careful with advice written for doctors.
If a pharmacy or NHS body employs you under PAYE, your NHS Pension Scheme contributions are deducted from that pay before you receive it, and the tier you fall into depends on your pensionable pay. That is handled by your employer, not through your Self Assessment return.
If you are genuinely self-employed and invoicing, that locum income generally is not NHS pensionable in the way a salaried role is, and the freelance GP locum pension route run through Primary Care Support England (PCSE) does not automatically apply to pharmacists. Because the rules and contribution tiers are set by NHSBSA and your employer rather than HMRC, and they are updated each April, do not rely on a fixed figure from a tax article.
The practical steps:
- Check your payslips to see whether NHS pension contributions are already being taken on your employed work.
- Confirm your current tier and contribution rate with your employer or directly with NHSBSA, since these are reviewed annually.
- Remember that employee pension contributions on PAYE work usually receive tax relief at source, so they are not claimed again on your Self Assessment return.
If your situation mixes employed and self-employed income, getting the pension and tax treatment lined up correctly is fiddly, and it is the sort of thing we untangle for locum healthcare clients.
Illustrative example: a community locum's tax for 2026/27
Illustrative example. Imagine Sana works as a self-employed community locum pharmacist for the whole of 2026/27. She invoices pharmacies directly and has no separate PAYE job.
Her figures for the year:
| Item | Amount |
|---|---|
| Locum income invoiced | £52,000 |
| GPhC registration fee | £262 |
| Professional indemnity and subscriptions | £400 |
| CPD and training | £350 |
| Business mileage (8,000 miles at 45p) | £3,600 |
| Accountancy fees | £600 |
| Total allowable expenses | £5,212 |
Her taxable profit is £52,000 minus £5,212, which is £46,788.
Income Tax for 2026/27, using the £12,570 personal allowance and the 20% basic rate:
- Personal allowance: £12,570 taxed at 0%.
- Remaining profit: £46,788 minus £12,570 = £34,218, all within the basic rate band, taxed at 20% = £6,843.60.
Class 4 National Insurance at 6% on profit between £12,570 and £46,788:
- £46,788 minus £12,570 = £34,218 at 6% = £2,053.08.
So Sana's total for the year is roughly £6,843.60 of Income Tax plus £2,053.08 of Class 4 National Insurance, around £8,896.68. Because her profits are above the Small Profits Threshold, her Class 2 is treated as paid with nothing more to hand over.
Without the £5,212 of expenses, her profit would have been £52,000 and her Income Tax and Class 4 noticeably higher. The £3,600 mileage claim alone saves her £216 in Class 4 and £720 in Income Tax at the basic rate. These figures are illustrative; your own position depends on your income, your other earnings, and your actual costs.
What are the key deadlines and payments on account?
Self Assessment runs on fixed dates, and the penalties for missing them are automatic. The ones a locum pharmacist needs in the diary:
| Deadline | What it is |
|---|---|
| 5 October after the tax year | Register for Self Assessment if it is your first year |
| 31 October after the tax year | Paper tax return filing deadline |
| 31 January after the tax year | Online filing deadline and balancing payment due |
| 31 July | Second payment on account due (if applicable) |
Most locums file online, so the date that matters is 31 January. For the 2026/27 tax year, that means filing and paying by 31 January 2028.
Then there are payments on account. If your tax bill is £1,000 or more, and less than 80% of your tax was collected at source, HMRC asks you to pay towards next year's bill in two instalments, on 31 January and 31 July, each being half of your previous year's liability. The first year this hits often surprises locums, because you can effectively pay one and a half years of tax in a single January. Plan cash flow for it.
A useful habit is to set aside a fixed percentage of every invoice the day it lands, in a separate account, so the January and July bills are already covered. We help locum clients work out the right percentage for their income level.
Want your locum tax handled properly, from registration through to filing and payments on account? Book a free call with a Zmartly accountant and we will get you set up.
Frequently asked questions
Do I need to register for Self Assessment if locum work is my only income?
Yes. Self-employed locum income is not taxed at source, so you must register for Self Assessment, file a return each year, and pay your Income Tax and National Insurance yourself. Register by 5 October following the end of the tax year in which you started.
Can a locum pharmacist claim the GPhC registration fee against tax?
Yes. The General Pharmaceutical Council is on HMRC's List 3 of approved professional bodies, and relief is due under section 343 ITEPA 2003 for entry to or retention on the Register of Pharmacists. Because you must be registered to practise, the fee is an allowable expense against your locum profit.
What mileage rate can I claim for travel between pharmacies?
If you use your own car for business travel to temporary workplaces, you can claim HMRC's approved mileage rate of 45p per mile for the first 10,000 business miles in the tax year and 25p per mile after that. Your ordinary commute to a regular, fixed workplace is not allowable.
Do I pay National Insurance on my locum income?
Yes. For 2026/27 you pay Class 4 National Insurance at 6% on profits between £12,570 and £50,270, and 2% above that. Class 2 is treated as paid once your profits reach the £7,105 Small Profits Threshold, so there is usually nothing extra to pay separately.
When is my locum tax actually due?
For the 2026/27 tax year, your online return and balancing payment are due by 31 January 2028. If you make payments on account, a second instalment is due by 31 July. Payments on account apply when your bill is £1,000 or more and less than 80% of your tax was collected at source.
