Locum work

A locum covers a vacant post, sickness, parental leave or a busy spell for a set period. In the public sector the word mostly means doctors and pharmacists. You can locum through an NHS trust’s own staff bank, through an agency, or as a self-employed contractor, and the route decides how you are paid, taxed and protected.

Who works as a locum

Doctors of every grade do it. Resident doctors pick up extra shifts on top of a training post, specialty and specialist (SAS) doctors and consultants cover gaps between substantive jobs, and GPs locum in surgeries, out-of-hours services and urgent treatment centres. Some doctors locum full time for years because they control where and when they work.

Pharmacists locum mostly in community pharmacies, covering shifts for chains and independents. Hospital pharmacy departments use them too, usually through an agency or the trust bank. For both professions the practical questions are the same: who pays you, on what terms, and who is responsible for your tax.

The three main routes

Trust bank

A trust’s bank (a staff bank or internal locum bank) pays you directly through its payroll. For those shifts you are a worker or employee, income tax and National Insurance come off through PAYE, and you can usually stay in the NHS Pension Scheme. Each trust sets its own bank rates for locum doctors, often with reference to national guidance, so they differ from place to place. The guide to NHS bank work covers how banks recruit and pay.

Agency

An agency finds you shifts and pays you, either through its own payroll or through an umbrella company. After 12 weeks in the same role with the same hirer, agency workers are entitled to the same basic pay and conditions as comparable permanent staff. From day one you can use shared facilities and see the hirer’s job vacancies. NHS England caps what trusts in England can pay agencies for locum shifts, and trusts need senior sign-off to break the caps. Agency work vs bank work sets the two side by side.

Self-employed or limited company

Many GP and community pharmacy locums invoice directly as sole traders, and some work through their own limited company. For public sector engagements, NHS trusts included, the off-payroll working rules (IR35) leave the decision on employment status with the public body. If the trust decides the role is “inside IR35”, tax and NI are deducted before you are paid, even though you invoice through a company.

Tax and National Insurance

Through a bank or agency on PAYE, tax works as it does in any job. A second job alongside a substantive post often gets a BR tax code, which tax when you have two jobs explains.

Self-employed locums register for Self Assessment by 5 October after the end of the tax year in which they started, and file online by 31 January. Income tax uses the normal bands: 20% basic rate on income from £12,571 to £50,270 in England, Wales and Northern Ireland, with different Scottish rates. Class 4 National Insurance for 2026/27 is 6% on profits from £12,570 to £50,270 and 2% above that. Class 2 is voluntary at £3.65 a week.

Allowable business costs include professional indemnity, registration fees and travel between work sites. HMRC’s rules on this are detailed, so check with an accountant or HMRC before you claim. Nothing is deducted before you are paid, so you need to set tax money aside yourself.

Pensions

Bank shifts in an NHS trust usually count as pensionable pay in the NHS Pension Scheme. Contribution rates depend on your total annual pensionable pay and run from 5.2% up to 12.5% in England and Wales in 2026/27.

GP locums in England and Wales can pay into the scheme for NHS work using its locum forms, which the practice and the locum both complete. Agency work and limited company work do not normally count. Locum pharmacists in community pharmacy sit outside the NHS scheme because the pharmacy is a private business, so any pension saving is down to you. The NHS Pension Scheme guide explains the tiers.

Registration, revalidation and indemnity

Locum doctors still need GMC registration and a licence to practise, and must revalidate through a designated body. Without a substantive post, that might be a locum agency or another organisation with a responsible officer. The GMC has a route for doctors with no connection at all, but it takes more organising. Keep your appraisal evidence up to date yourself, because nobody else will chase it.

Pharmacists must be registered with the General Pharmaceutical Council and meet its revalidation requirements each year. Community pharmacy chains usually check your registration and right to work before your first shift.

Indemnity depends on the setting. In England, NHS work in hospital trusts is covered by the trust’s clinical negligence arrangements, and NHS general practice work by the state-backed scheme for GPs. Private work falls outside both, and you still need defence organisation membership for regulatory and other matters. Locum pharmacists should check what the pharmacy’s cover includes before relying on it.

Day to day

You choose your shifts, turn down places you did not like and can take long breaks. The costs are easier to miss. A self-employed locum may get no paid holiday, sick pay or parental pay, and even a bank worker’s entitlements are based on hours worked. Holiday for irregular-hours workers accrues at 12.07% of hours worked and can be paid as rolled-up holiday pay.

Every new site means unfamiliar systems, often with no IT log-in and little induction, so the first shift anywhere runs slow. Experienced locums keep a short list of questions for arrival: who the senior on call is, how to get at results and prescribing, and where the emergency equipment is.

For a dispute over unpaid invoices, cancelled shifts or employment status, start with the agency’s or trust’s own process. ACAS can explain your rights as a worker, a union such as the BMA or the Pharmacists’ Defence Association can advise members, and HMRC deals with tax status questions.