Locum pharmacist tax and expenses: 2026/27 guide

Register for Self Assessment on time

You must register once your self-employment income goes over £1,000 in a tax year. Tell HMRC by 5 October after the end of that tax year: 5 October 2027 for income earned in 2026/27. Registering late can mean a penalty.

Returns for 2025/26 are due by 31 October 2026 on paper and 31 January 2027 online. The tax is also due by 31 January 2027.

Plan for payments on account

If last year's Self Assessment bill was £1,000 or more, HMRC usually asks for two payments on account. Each is half of last year's bill, including Class 4 National Insurance, due on 31 January and 31 July.

You do not make them if more than 80% of last year's tax was paid another way, such as through PAYE. Put money aside from each payment you receive so the January bill is covered.

Claim allowable expenses

You can deduct costs you incur for your locum work. Travel between home and a regular place of work is not allowable. Whether journeys from home to different pharmacies count depends on the facts, so keep a mileage log and take advice if you are unsure.

Keep receipts and records for at least five years after the 31 January deadline for that year's return. If you use the £1,000 trading allowance instead, you cannot claim expenses as well.

• Fuel, parking, train and bus fares for business journeys
• Professional indemnity insurance premiums
• Professional body subscriptions related to your work
• Training that updates skills you already use

Use the mileage rate if it suits you

Sole traders can use simplified expenses instead of working out actual vehicle costs. For 2026/27 the flat rate for cars and vans is 55p a mile for the first 10,000 business miles and 25p after that. It was 45p before 6 April 2026.

You cannot use the flat rate for a vehicle you have already claimed capital allowances on, and limited companies cannot use simplified expenses.

National Insurance and VAT

In 2026/27, Class 4 National Insurance is 6% on profits between £12,570 and £50,270 and 2% above that. With profits of £7,105 or more, Class 2 is treated as paid, so there is nothing extra to pay.

You must register for VAT if your taxable turnover goes over £90,000 in any rolling 12 months. Whether a locum pharmacist's services are exempt from VAT depends on the work, so take advice if your turnover nears the threshold.

Making Tax Digital for Income Tax

From 6 April 2026, sole traders with qualifying income over £50,000 must keep digital records and send quarterly updates through compatible software. The threshold falls to £30,000 from April 2027 and £20,000 from April 2028.

Qualifying income is your self-employment and property income before expenses, so compare the threshold with your total locum fees.