Working as a locum doctor means you can claim a wide range of business expenses to reduce your tax bill. Knowing what locum doctor expenses you can claim, and the HMRC rules that decide each one, is one of the simplest ways to keep more of your day rate and stay fully compliant.

The governing principle is short: an expense is allowable only where it is incurred wholly and exclusively for your profession (ITTOIA 2005 s.34). For a self-employed locum that covers a lot of ground, from mileage between sites to medical indemnity and professional fees. This guide is written for the freelance, self-employed locum filing a Self Assessment return (SA103); if you work through your own limited company the rules on expenses and extraction differ, and we link to the dedicated guide below.

Travel and Mileage Between Sites

Travel is usually the largest category of locum doctor expenses you can claim. You can deduct the cost of travel between work locations, but not your ordinary commute to a regular workplace.

Allowable travel expenses include:

  • Mileage in your own car at HMRC approved rates, 55p per business mile for the first 10,000 miles in 2026/27, then 25p per mile (the first-tier rate rose from 45p on 6 April 2026)
  • Public transport between assignments
  • Parking at work locations
  • Taxi fares where public transport is not practical
  • Congestion charges and tolls

If you cover three different practices in one week, you can claim the mileage travelling between those sites. What you cannot claim is the journey from home to your first regular site of the day, or from your last site back home, that is ordinary commuting and is specifically not deductible.

Keep a contemporaneous mileage log: date, destination, miles and the business purpose of each trip. A logbook or app makes this painless and is exactly the evidence HMRC expects if it asks. The 55p/25p approved rates are designed to cover fuel, servicing, insurance and wear, so if you use them you do not also claim those running costs separately for the same vehicle.

Accommodation and Subsistence

When you work too far from home to return the same day, a locum can claim reasonable accommodation and meal costs.

Claimable accommodation expenses:

  • Hotel or B&B costs when working away overnight
  • Reasonable meals while away from home on business
  • Incidental costs such as a business phone call or paid internet access

HMRC judges "reasonable" on the circumstances. A higher nightly hotel rate in central London can be reasonable where the same figure in a small town would not be. A week-long block of sessions a long way from home clearly justifies an overnight stay; a single local day shift would not. Keep every receipt and note the business reason for being away.

Medical Indemnity, the GMC Fee and Professional Subscriptions

Several mandatory and optional professional costs are allowable, and indemnity is often the single largest after travel.

Professional costs you can claim:

  • Medical indemnity with the MDU, MPS or MDDUS
  • The GMC annual retention fee (the fee that maintains your registration and licence to practise)
  • Royal College and specialty membership fees on HMRC's approved List 3
  • BMA subscription where used for your profession (on List 3)
  • Locum agency or chambers registration fees

There is an important medical-specific point on indemnity. Since 1 April 2019 the Clinical Negligence Scheme for General Practice (CNSGP) provides state indemnity for NHS general-practice clinical negligence in England at no subscription. So if you are a GP locum, your own paid indemnity now mainly covers your private or non-NHS clinical work and non-clinical or regulatory matters (for example Good Samaritan acts, complaints, inquests and GMC matters), rather than NHS clinical negligence itself. It is still deductible, but it is worth checking you are paying for the cover you actually need rather than duplicating what CNSGP already provides for your NHS sessions. Note that the GMC retention fee is deductible, but restoration and penalty fees are not.

Professional Development and Training

Keeping your skills current is part of being a locum, and genuine CPD relevant to your current practice is allowable.

Training and development expenses include:

  • Medical conferences and seminars
  • CPD courses and workshops
  • Medical journals and publications
  • Online learning platforms and clinical reference apps
  • Examination fees for qualifications relevant to your work

A GP locum attending a clinical update course can claim the course fee, plus the travel and accommodation if an overnight stay is needed. The test is that the training maintains or updates skills used in your current locum work; training to enter an entirely new field is treated differently, so flag anything borderline with your accountant.

Equipment and Technology

Locums often supply their own kit, and most of it is allowable, though sometimes through capital allowances rather than as a straight expense.

Equipment expenses include:

  • Stethoscopes, medical bags and diagnostic instruments
  • Tablets or laptops used for work
  • Clinical software and apps
  • Mobile phone and broadband (business proportion only)
  • Specialist protective clothing (not everyday clothes)

Equipment with a lasting use is claimed through capital allowances. In practice the Annual Investment Allowance gives 100% relief on up to £1,000,000 of qualifying plant and machinery in the year, so most locums can write off a laptop or instruments in full in the year of purchase. Cars are excluded from these allowances (you use the mileage rate or actual-cost method instead).

Home Office and Administrative Costs

Most locums do their admin, invoicing and record-keeping from home, so a proportion of home running costs is allowable.

Home office expenses:

  • A proportion of utility bills (electricity, gas, water)
  • Broadband and phone (business proportion)
  • Office supplies and stationery
  • Accountancy and bookkeeping fees
  • Business insurance

There are two ways to claim the use of home. HMRC simplified expenses give a flat monthly rate based on the hours you work from home: £10 a month for 25 to 50 hours, £18 for 51 to 100 hours and £26 for 101 or more hours (the flat rate excludes phone and broadband, which you claim separately on a business-proportion basis). Alternatively, you can calculate the actual business proportion of your home running costs, which is often worth more if you use a dedicated room. Pick whichever gives the better result and keep the supporting records.

What You Cannot Claim

Knowing what is not allowable matters just as much.

Non-allowable expenses include:

  • Ordinary commuting to a regular workplace
  • Personal meals and entertaining
  • Everyday clothing that could be worn outside work
  • Fines and penalties (including GMC restoration or penalty fees)
  • Personal insurance or your own medical costs

The "wholly and exclusively" test runs through all of this: where an expense has a real personal element, only the identifiable business proportion is allowable.

Record Keeping and Making Tax Digital

HMRC requires you to keep evidence for every expense you claim, and poor records are the most common reason a claim is disallowed.

Essential records include:

  • Receipts and invoices
  • Bank statements showing the payments
  • A mileage log with dates and destinations
  • A note of the business purpose of each expense
  • Evidence of business use for any mixed personal and business item

From 6 April 2026, Making Tax Digital for Income Tax applies to self-employed sole traders with qualifying income over £50,000, bringing mandatory digital record-keeping and quarterly updates (the threshold falls to £30,000 from April 2027 and £20,000 from April 2028). Most full-time locums sit above £50,000, so are in scope from April 2026; a locum trading through a limited company is outside MTD for Income Tax (it is an income-tax regime, not corporation tax). Photograph paper receipts at once and store them in compatible software so quarterly reporting is straightforward.

How Your Claims Translate Into Tax Saved

Every allowable pound reduces your taxable profit, and the saving is at your marginal rate. A higher-rate taxpayer saves 40p of income tax on each pound claimed and an additional-rate taxpayer 45p, before National Insurance.

As a general illustration, a self-employed locum with profits in the higher-rate band who claims £8,000 of genuine expenses removes that £8,000 from charge, saving £3,200 of income tax at 40%. There is a further Class 4 National Insurance saving on top, because Class 4 is charged on profit after expenses: 6% on profits between £12,570 and £50,270 and 2% above £50,270 in 2026/27. Note that Class 2 National Insurance is no longer a required payment from 6 April 2024, so there is no separate weekly flat-rate charge to factor in where your profits are at or above the small profits threshold (your state pension record is still credited). These figures are illustrative only; your own position depends on your total income and circumstances.

Limited Company, IR35 and NHS Pension Considerations

Expenses are only one part of a locum's tax position. Three related decisions interact with them, and each has its own dedicated guide:

  • Trading through a limited company. A company changes how you claim costs and extract profit, and the maths shifted again when the dividend rates rose on 6 April 2026. See locum doctor limited company pros and cons.
  • IR35 and off-payroll working. If you use a personal service company, the hirer (an NHS Trust, or a medium or large private hospital) usually decides your IR35 status and issues a Status Determination Statement. IR35 has not been abolished, so this still matters for company-route locums. See locum doctor IR35: what you need to know.
  • NHS pension. A freelance GP locum pensions NHS income via Locum forms A and B. Crucially, income routed through a limited company is not NHS-pensionable, so any company tax saving must be weighed against lost pension accrual. See NHS pension for locums: form A and form B.

This article is general information for UK doctors, not personal tax advice. As a firm that specialises in medical and GP accounting, we can help you identify every allowable expense, keep MTD-ready records and claim the right relief while staying compliant with HMRC. Get in touch to talk through your locum tax position.