New to Locuming

Getting Started as a Locum GP

Prerequisites and four financial steps for new locum GPs — plus answers to the questions everyone has.

Before You Start: Non-Negotiable Prerequisites

These must be in place before your first locum session. The financial steps below don't matter if you can't legally work.

NHS Performers List

You cannot legally provide NHS primary care services as a locum unless your name is on the NHS Performers List for the country where you're working (England, Scotland, Wales, or Northern Ireland). Applications can take several weeks — do this as soon as you know you'll be locuming. New CCT holders often miss this and lose their first booked sessions as a result.

England: NHS England (nhsbsa.nhs.uk). Scotland: NHS NSS. Wales: NHS Wales Shared Services Partnership.

Medical Indemnity Insurance

You must have adequate indemnity cover before seeing any patient. For locum GPs this means either a claims-made or occurrence-based policy from MDU, MPS, or MDDUS. Confirm you have locum-specific cover — a salaried GP policy typically does not cover sessional locum work. The premium is a fully allowable business expense.

GMC Registration (confirm it's current)

Ensure your GMC registration is live and your licence to practise is current. Check your revalidation date and appraisal status — practices increasingly verify this before booking. If you're newly registered, confirm your Responsible Officer arrangements for revalidation as a locum.

Register with HMRC for Self Assessment

As soon as you earn any self-employed locum income, you become responsible for reporting it to HMRC. You must register by 5 October following the end of the tax year in which you started. For example, if your first session is in September 2025 (tax year 2025/26), you must register by 5 October 2026.

Do it online at gov.uk — search "register for Self Assessment". It takes about 10 minutes. You'll receive a Unique Taxpayer Reference (UTR) by post within two weeks. Keep it safe.

Don't wait until January. Late registration is technically a notifiable failure and late filing penalties start at £100. Register early so you have time to set up your online account and gather your records.

Open a Separate Bank Account for Locum Income

You don't legally need a separate business account as a sole trader, but it makes your life significantly easier. With all locum payments going into one account and all locum expenses coming out of it, your accounts at year-end take minutes rather than hours to reconstruct.

A basic current account at any bank works — you don't need a dedicated "business" account with monthly fees. Some locums use a simple personal account they keep purely for locum activity. Others use Monzo, Starling, or similar to categorise spending automatically.

The key habit: every locum payment in, every locum expense out — nothing else touches that account.

Understand You Are a Sole Trader by Default

Most new locum GPs are automatically self-employed sole traders. There's nothing to register beyond HMRC Self Assessment — you don't need to set up a company or tell Companies House anything. You trade under your own name, you're personally responsible for your tax, and you keep all profits after tax and National Insurance.

A Ltd company is an option some locums consider at higher income levels (broadly £50,000+), but it adds complexity: you'll need a separate company bank account, annual accounts filed at Companies House, and an accountant. Don't over-complicate things in year one.

Sole trader

Default for all new locums. Simple, low admin.

Ltd company

Requires Companies House registration. More admin.

PAYE

Only if an agency deducts tax before paying you.

Start Tracking Expenses from Session One

Every allowable business expense reduces your taxable income — which means less tax. The common ones for locum GPs are:

→ Mileage: 45p/mile for the first 10,000 miles per year, 25p after. Log every journey.
→ Medical indemnity: MDU, MPS, or MDDUS premiums — fully deductible
→ GMC annual retention fee: £433/year — mandatory for every GP, fully deductible
→ BMA / Royal College subscriptions
→ CPD and courses: any training required for your locum work
→ Accountancy fees: the cost of your accountant is itself deductible

Use the expenses tracker on this site — it includes a mileage calculator that applies the correct HMRC rate automatically. Or use a spreadsheet. The format doesn't matter; the discipline does.

Keep receipts (or at least records). HMRC can request evidence going back six years.

How Does the Money Actually Flow?

This is the question every new locum asks, and the answer is simpler than it seems:

Step 1

You do a session. The practice logs it on their system. Some practices use a booking form; some just call. Make sure there's a record of what you're owed.

Step 2

You invoice the practice (or they pay from their own records). A basic invoice with your name, date, session description, and amount is sufficient. Most practices pay within 30 days — some immediately. You are not registered for VAT (locum medical services are VAT-exempt).

Step 3

The practice pays you gross — no tax is deducted at source (unlike PAYE employment). The full day rate lands in your bank account.

Step 4

You set aside tax yourself. A common rule of thumb is 25–30% of gross income into a savings pot. This covers income tax, Class 4 NI, and the first Payments on Account instalment when January comes.

Step 5

January 31st: you file your Self Assessment return and pay what you owe. Use the tax calculator throughout the year to estimate your liability and avoid surprises.

NHS Pension — Don't Opt Out

Before your first session: To do NHS GMS/PMS sessional work and be eligible for NHS pension contributions, you must be on the NHS Performers List. New GPs should confirm their name has been added before accepting sessions. Contact your local NHS England regional team if you need to check or be added.

If you are doing NHS GMS/PMS sessions, you can remain in the NHS Pension Scheme as a locum GP. The practice contributes 14.38% of your pensionable pay — that is free money you lose permanently if you don't participate.

The paperwork is:

Locum A (SD55): you prepare and submit this to NHSBSA, after getting the practice to countersign it. The practice confirms your sessions and fees — you are responsible for submission. You can submit per-session or quarterly; the annual deadline is 28 February.
Locum B (SD55B): your annual declaration of total pensionable pay for the year

NHS Pension calculator and form guide →

⚠️ Watch Out for Payments on Account

Your first January tax bill will be larger than expected — roughly 1.5× your annual tax liability. HMRC asks you to pay your current year's tax plus the first instalment of next year's tax all at once. This surprises nearly every new self-employed GP.

Set aside 25–30% of every payment from day one. Read the full explanation →

Ready to estimate your take-home pay?

Use the Tax Calculator →