Locum Doctor Tax Guide 2026/27: Self Assessment, Expenses and IR35
Complete UK tax guide for GP and hospital locum doctors in 2026/27 -- Self Assessment, allowable expenses, NHS Pension options, VAT threshold and IR35 risks explained with real examples.
Working as a locum doctor -- whether as a self-employed GP locum covering practices across a region, or as a hospital doctor taking bank and agency shifts -- creates a specific set of tax responsibilities that employed NHS consultants never encounter. Understanding self-employment taxation, allowable expenses, NHS Pension access and IR35 is essential to staying compliant and keeping as much of your income as possible.
This guide covers the key tax issues for locum doctors in the UK in 2026/27.
Self-Employed vs Employed Locum: The Key Distinction
Your tax treatment depends on how you are engaged:
| Engagement type | Tax treatment |
|---|---|
| Self-employed locum (sole trader) | Self Assessment, Class 2 and 4 NI, expenses deductible |
| Employed via agency or trust (PAYE) | Employer deducts tax, P60 issued, limited expenses |
| Limited company director | Corporation tax on profits, IR35 risk in NHS settings |
| NHS bank staff (directly employed) | PAYE, NHS Pension may apply |
Many locum doctors have mixed income in a single year -- for example, PAYE bank shifts at one trust and self-employed GP locum sessions. Both sources must be declared on a Self Assessment return, and together they determine your marginal tax rate.
Registering for Self Assessment
If you are working as a self-employed locum, you must:
- Register with HMRC as self-employed (online via government gateway)
- Obtain a Unique Taxpayer Reference (UTR) -- allow four to six weeks by post
- Complete a Self Assessment tax return for each tax year
- Pay any tax owed by the payment deadline
For the 2026/27 tax year (ending 5 April 2027):
- Online filing deadline: 31 January 2028
- Payment deadline: 31 January 2028 (with a further payment on account due 31 July 2028)
A Real Example: GP Locum Income in 2026/27
A GP locum working four sessions per week at £125 per session, 48 weeks per year:
- Gross income: £125 x 4 x 48 = £24,000
Typical allowable expenses:
| Expense | Annual cost |
|---|---|
| Professional indemnity (MDU/MPS) | £4,500 |
| GMC registration | £466 |
| BMA membership | £450 |
| Business mileage (6,000 miles x 45p) | £2,700 |
| CPD and conference fees | £500 |
| Accountancy | £600 |
| Total expenses | £9,216 |
Taxable profit: £24,000 - £9,216 = £14,784
Tax and NI on £14,784 profit:
| Personal Allowance | £12,570 |
| Taxable income | £2,214 |
| Income tax at 20% | £443 |
| Class 4 NI at 9% on £2,214 | £199 |
| Class 2 NI (£3.45 x 52 weeks) | £179 |
| Total tax and NI | £821 |
| Take-home after tax | ~£13,963 |
At this income level, the expenses turn what would be a moderate tax bill into a very small one. Use the income tax calculator to model your own figures with different session rates or expense levels.
Allowable Expenses for Locum Doctors
Expenses must be incurred wholly and exclusively for the business to be allowable against tax.
Professional costs:
- Professional indemnity insurance (MDU, MPS, MDDUS) -- typically the largest single expense
- GMC registration fee
- Royal College membership fees
- BMA or other medical association subscriptions
Travel to temporary workplaces:
- Mileage at 45p per mile (first 10,000 miles), 25p thereafter
- Public transport and parking at work locations
- Travel from home to a regular, permanent base is not allowable
Education and CPD:
- Medical conference registration
- Online learning platforms and medical journals
- Mandatory training required for your current role
Equipment:
- Medical bag and clinical equipment purchased for work
- A proportion of a laptop or phone where genuinely used for business
Home office:
- If you do NHS administration from home, you can claim a proportion of broadband and energy. HMRC allows flat rates of £10 per month (25-50 hours/month work) to £26 per month (over 100 hours/month).
NHS Pension for Self-Employed GP Locums
Self-employed GP locums can join the NHS Pension Scheme in England and Wales as type 2 medical practitioners. Unlike employed NHS staff who have contributions deducted automatically, self-employed locums:
- Pay both the employee contribution AND a notional employer contribution from their own income
- Complete an annual certificate of pensionable income
- Accumulate pension credits based on career average earnings in NHS work
The combined contribution (employee plus notional employer) at 2026/27 rates for GP locums totals approximately 22% to 28% of NHS pensionable profit. This is a significant outlay, but the resulting defined benefit is extremely valuable.
Monitor total pension input against the Annual Allowance (£60,000 standard limit in 2026/27). GPs with both NHS Pension and any other pension can face Annual Allowance charges if total pension growth exceeds this limit.
IR35 and Hospital Locums
IR35 is the off-payroll working legislation targeting contractors working through their own personal service company (PSC -- typically a limited company). Since April 2021, NHS trusts are responsible for determining the IR35 status of all off-payroll workers they engage.
Inside IR35: PAYE is applied by the trust or agency. The locum receives net pay after tax and NI, and the limited company provides no tax advantage. The locum is effectively treated as an employee for tax purposes.
Outside IR35: Unlikely in most NHS trust settings. The high level of supervision, the requirement to use trust systems and equipment, and the nature of substituting for employed medical staff all indicate an employment-like relationship that typically falls inside IR35.
Sole trader GP locums are not affected by IR35 because they do not operate through a PSC. They bill directly as self-employed individuals.
VAT Registration for Locum Doctors
| Income type | VAT treatment |
|---|---|
| GP locum clinical sessions | Exempt -- does not count towards threshold |
| Hospital bank clinical shifts | Exempt -- does not count towards threshold |
| Medico-legal reports and insurance examinations | Standard-rated 20% -- counts towards threshold |
| Expert witness work | Standard-rated 20% -- counts towards threshold |
| Non-clinical training or consultancy | Standard-rated 20% -- counts towards threshold |
Registration is compulsory when taxable (non-exempt) turnover exceeds £90,000 in a rolling 12-month period. If you do significant medico-legal work alongside clinical locum sessions, track your non-exempt income carefully throughout the year.
Payments on Account
Once your Self Assessment tax bill exceeds £1,000, HMRC requires advance payments:
- 31 January: Pay the current year balance plus 50% advance for next year
- 31 July: Pay the second 50% advance for next year
Example: First-year locum with a £4,000 tax bill for 2026/27. On 31 January 2028 they owe £4,000 + £2,000 advance = £6,000 in one payment.
The solution is simple: set aside 25-30% of every payment you receive into a separate savings account throughout the year. Treat this money as already spent -- it belongs to HMRC.
Record-Keeping for Locum Doctors
Keep records for at least six years:
- Invoices issued to practices and agencies, showing dates and amounts
- Bank statements confirming income received
- Receipts and invoices for all expenses claimed
- Mileage log with date, origin, destination, purpose and distance for every journey
- NHS Pension annual statements
- P60s and payslips from any employed work during the same year
Frequently asked questions
Do locum doctors need to complete a Self Assessment tax return?
Yes, if you work as a self-employed locum. Any self-employed income must be declared to HMRC via Self Assessment regardless of the amount. You must register by 5 October in the year after you first receive self-employed income. For income earned in the 2026/27 tax year (to 5 April 2027), the registration deadline is 5 October 2027 and the online filing deadline is 31 January 2028. You will also need a Unique Taxpayer Reference from HMRC, which can take four to six weeks to arrive.
What is the difference between self-employed and employed locum income?
Self-employed locums invoice GP practices or agencies directly and handle their own tax and National Insurance via Self Assessment. Employed locums receive a payslip with PAYE deductions already made by the payer. Some hospital locum doctors are engaged via agencies on PAYE even when they have their own limited company. The distinction matters for expenses, NHS Pension access, IR35 status, and VAT registration. Many locums have both self-employed and employed income in the same tax year.
Can locum GPs join the NHS Pension Scheme?
Self-employed GP locums can join the NHS Pension Scheme in England and Wales as a type 2 medical practitioner. Contributions are calculated as a percentage of NHS pensionable profit, and both the employee and a notional employer contribution must be paid by the locum. The scheme is a defined benefit arrangement based on career average earnings and is extremely valuable. Annual allowance charges can apply when pension growth is high -- particularly relevant for experienced GPs with existing large pension pots.
What expenses can locum doctors claim against tax?
Allowable expenses for self-employed locum doctors include: professional indemnity insurance (typically £3,000 to £8,000 per year for GPs), GMC registration fees (£466 per year in 2026), medical defence union or BMA subscriptions, CPD courses and conference fees, medical equipment used at work, business mileage at 45p per mile for the first 10,000 miles, accountancy fees, and a proportion of home office costs if you carry out administrative work from home.
Does IR35 apply to hospital locum doctors?
IR35 is a real risk for hospital locum doctors who work through a personal service company (PSC). NHS trusts must carry out status determinations for all off-payroll workers. If a trust determines your engagement is inside IR35, the trust or the agency must deduct PAYE tax and NI before paying you. Many hospital locum engagements fall inside IR35 because of the level of supervision, direction and control within an NHS trust environment. Self-employed sole trader GP locums operating without a PSC are not affected.
When do locum doctors need to register for VAT?
VAT registration is compulsory when your taxable turnover exceeds £90,000 in a rolling 12-month period. Medical services provided by a qualified doctor to patients are VAT-exempt and do not count towards the threshold. However, other income such as insurance medico-legal reports, expert witness fees, and non-clinical consultancy is standard-rated at 20% and does count. Monitor your non-exempt income carefully if you do significant private or medico-legal work alongside locum clinical sessions.
What are payments on account for locum doctors?
Payments on account are advance tax payments made in January and July each year. Once your Self Assessment tax bill exceeds £1,000, HMRC requires two advance payments each equal to 50% of the previous year tax bill. For a locum with a large first-year bill this can be a shock -- the January payment covers the year just ended plus a 50% advance for the following year. Build a tax reserve of 25 to 30% of gross income throughout the year to avoid a cash flow crisis.
What BMA rates apply to GP locums in 2026/27?
The British Medical Association publishes recommended minimum rates for GP locums, updated regularly. In 2026/27, the BMA suggests rates of approximately £100 to £170 per clinical session (typically a three-hour period) for experienced GPs, though actual rates vary significantly by region, time of day, and local demand. Rural and London areas often pay above these rates. Rates for out-of-hours and weekend sessions are typically higher than standard daytime rates.
How much tax does a GP locum earning £19,000 profit pay in 2026/27?
A self-employed GP locum with taxable profits of £19,000 would pay income tax of £1,286 -- that is 20% on (£19,000 minus the £12,570 Personal Allowance = £6,430). Class 4 NI at 9% on £6,430 adds £579. Class 2 NI applies above the Small Profits Threshold -- at £3.45 per week that is £179 annually. Total tax and NI approximately £2,044. Take-home approximately £16,956. These figures exclude any student loan repayments.
Should locum doctors use a limited company or work as sole traders?
For self-employed GP locums, working as a sole trader is simpler and often sufficient. A limited company provides some tax efficiency through dividends but involves more administrative cost, accounting fees, and Companies House obligations. Tax savings from incorporating are smaller than they once were because corporation tax and dividend tax have both increased. More importantly, hospital locum engagements through a PSC attract IR35 scrutiny. Many locums operate as sole traders for GP sessions and avoid the IR35 complexity entirely.
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