GP Locum Invoicing: A Practical UK Guide

Quick answers

The short version

What should a GP locum invoice include?: Identify you and the practice, give the invoice a unique number and date, list the session dates and agreed fees, show any separately agreed expenses, state the total and payment terms, and provide bank details plus a payment reference.
How quickly should I invoice?: Send the invoice as soon as the agreed billing period ends—often after the session or at month end. A fixed weekly or monthly routine reduces forgotten work and gives the practice a clear starting date for its payment process.
What payment terms should I use?: Use the terms agreed before the work. Fourteen or 30 days are common commercial choices, but there is no airGP default that is right for every engagement. Put the due date or unambiguous terms on the invoice.
Should expenses and mileage go on the invoice?: Only include costs the practice agreed to reimburse. Show parking, mileage or other items separately from the clinical fee and keep the supporting record. Do not assume business mileage claimed for tax is also chargeable to a practice.
How does airGP help?: airGP can create invoice records from sessions, generate, download and email PDF invoices, track unpaid, paid and cancelled status, record paid dates, retain invoice and email history, and connect those records with expenses, mileage, pension logging and tax exports.

What a GP locum invoice should include

A practice should be able to identify the work, approve it and pay it without asking what the invoice relates to. Your accountant should also be able to follow the same document later. The exact legal requirements can vary with your business structure, so confirm those points professionally; the list below is a practical starting structure rather than legal advice.

Use the same identity and practice naming on every related record. If a booking email says “Riverside Medical Centre” but the invoice says “Riverside Surgery” and the bank receipt says “Riverside PCN”, retain enough context to show they relate to the same customer. Consistency matters more once you work across several sites.

Your name and, if useful to the practice, your GMC number.
Your trading name and sole-trader or limited-company details where relevant.
Your correspondence address or registered business address, as appropriate.
The practice's correct name, billing address and relevant contact.
A unique invoice number, invoice date and explicit due date or payment terms.
Each session date, a plain description of the work and the agreed session or hourly fee.
Reimbursable expenses and practice-charged mileage as separate line items.
Any useful pension-related note, without presenting it as a decision on eligibility.
Subtotal, any applicable tax treatment, and the total amount due.
Bank details and the reference the practice should quote when paying.

A reliable session-to-payment workflow

The safest workflow starts before the session. Confirm the fee, what the session covers, whether agreed costs can be recharged, who receives the invoice, the intended payment terms and the pension context. A polished invoice cannot resolve an ambiguity that was never agreed.

After the work, treat the session record as the source. Generate the invoice from checked session information, then reconcile the payment back to that invoice. The paid date should be the date you can support from your bank record, not the day you happened to tidy the spreadsheet.

Agree the rate, reimbursable costs, invoicing contact, payment terms and pension position before the session.
Log the completed session against one consistently named practice.
Check dates, fee, description, expenses and mileage before creating the invoice.
Generate the invoice and email the PDF or download it for your agreed delivery route.
Keep the sent invoice and communication trail; do not overwrite the only copy.
Review the relevant bank receipt and mark the invoice paid with the actual paid date.
Leave unmatched invoices unpaid and investigate part-payments or combined payments rather than forcing a match.
Reconcile invoice, expense and mileage records for tax, accountant and MTD preparation.

Common invoicing mistakes—and why they matter

Most invoice problems are small data failures repeated over time. A missed session delays income. A duplicate number makes correspondence ambiguous. A vague total makes approval slower. A missing paid date weakens cash-basis records and makes month-end reconciliation harder.

Do not use a status as a substitute for evidence. “Paid” should have a matching receipt and date; “sent” should have a PDF or email trail; “pensionable” should reflect the position you have established rather than a guess made during invoicing.

Forgetting to invoice a completed session because the diary and invoice list are separate.
Duplicating invoice numbers after copying an old Word document.
Mixing paid and unpaid items in a spreadsheet without a dependable status or paid date.
Rolling parking, mileage or other expenses into the session fee so nobody can see the calculation.
Treating pensionable and non-pensionable work as interchangeable.
Creating duplicate practice records with inconsistent names and contacts.
Chasing a late payment without the invoice number, dates, amount, original email or due date.

Six realistic GP locum invoice scenarios

For one session, a single dated line with the agreed fee may be enough. If you work several sessions for the same practice, one monthly invoice can be clearer when the practice accepts that arrangement—but retain every individual work date. If parking was agreed, add “Parking reimbursement” as its own line rather than silently increasing the session fee.

Mileage needs two distinct questions: did the practice agree to reimburse this journey, and are you keeping a separate mileage record for tax review? One does not automatically imply the other. If the practice pays mileage, show the agreed miles, rate and amount on the invoice. Keep your broader mileage log separately.

For pensionable work, preserve the individual session, practice and fee context needed for later pension administration. An invoice note can help identify the arrangement, but airGP does not decide eligibility or submit pension forms to an NHS body. At month end, it is normal to have a mixture of paid and unpaid invoices; keep the statuses separate and carry forward only the genuinely outstanding items.

Example: three sessions plus agreed parking

Invoice AGP-2026-041 · Invoice date 30 June 2026 · Due 14 July 2026
10 June — GP locum session — £600.00
17 June — GP locum session — £600.00
24 June — GP locum session — £600.00
24 June — Agreed parking reimbursement — £8.50
Total due — £1,808.50
Payment reference — AGP-2026-041

Where airGP fits

airGP is designed to keep the administrative chain connected. You can create invoice records from session data, group relevant sessions, generate a PDF, download it or email it from the invoice workflow, and later see whether the invoice is unpaid, paid or cancelled. When payment arrives, you can record the paid date. Invoice email logs and payment-reminder emails provide context for follow-up.

The same source records can support practice-level billing history, expense and mileage review, pension logging, and tax or accountant exports. That reduces re-keying; it does not remove your responsibility to check the records, agree terms, reconcile the bank and obtain advice where needed.

Session-to-invoice records and multi-session invoices for the same organisation.
PDF invoice generation, download and email workflows.
Unpaid, paid and cancelled invoice status plus paid-date tracking.
Invoice history, email logs and payment-reminder emails.
Connected expenses, mileage, pension records and tax-report exports.

What airGP does not do

airGP is an administrative and record-keeping tool. It does not provide tax, legal, accounting or pension advice; decide whether work is pensionable; guarantee that a practice will pay; replace your accountant; or submit ordinary locum invoices to NHS bodies on your behalf.

The product can help you produce a clearer trail, but the invoice remains yours. Check the recipient, amounts, bank details and terms before sending it, and use the appropriate professional or official route for disputed debts, tax treatment and pension eligibility.

A monthly GP locum invoicing checklist

Set a recurring review date even if you invoice after every session. The purpose is to catch gaps between clinical work, invoices, bank receipts and downstream records before they become a year-end reconstruction exercise.

Compare completed sessions with generated invoices and create anything missing.
Review unpaid invoices against their agreed due dates.
Send concise reminders for overdue invoices and retain the communication trail.
Match bank receipts and record accurate paid dates.
Check that reimbursed expenses and mileage are itemised correctly.
Review pensionable status separately from the invoice payment status.
Investigate duplicate practice names, invoice numbers or unexplained totals.
Export or review the period's records for your accountant, tax or MTD workflow.

Frequently asked questions

GP locum invoice FAQs

What should I put on a GP locum invoice?

Include your business details, the practice details, a unique invoice number and date, each session date and description, agreed fees, separately itemised reimbursable costs, total due, payment terms, bank details and a payment reference.

Do GP locums need invoice numbers?

Use a unique, sequential or otherwise systematic reference for every invoice. It prevents ambiguity when a practice pays or queries an invoice and gives you a dependable audit trail. Confirm any structure-specific invoicing requirements with your accountant.

Should I invoice after every session or monthly?

Either can work if agreed with the practice. Invoicing promptly after each session improves immediacy; a monthly invoice can reduce admin for repeated work. Whichever you choose, list every session date and run a missing-invoice check.

What payment terms should a GP locum use?

Use the terms agreed with the practice before the work. Fourteen or 30 days are common choices, but suitability depends on the engagement. State a clear due date rather than relying on an assumption.

Can I include parking or mileage?

You can invoice costs the practice agreed to reimburse. Show them separately with enough detail to approve the amount. A tax mileage record and mileage chargeable to a practice are different records.

How do I chase a late GP locum invoice?

Check the due date and recipient, then send a polite reminder containing the practice, invoice number, session dates, amount and attached invoice. Escalate the tone and route proportionately while retaining every message. Seek professional advice for a dispute.

Should pensionable work appear differently?

Keep pensionable context identifiable and preserve the component session dates and fees. The invoice can include an agreed note, but invoicing software should not decide pension eligibility. Check current official guidance for your circumstances.

Can airGP replace my invoicing spreadsheet?

airGP can replace much of a session-to-invoice spreadsheet workflow by connecting sessions, practices, PDF invoices, statuses and paid dates. You still need to check entries and reconcile payments.

Can airGP help with tax records?

Yes. Structured session, invoice, payment, expense and mileage records can support tax and accountant exports, plus supported MTD workflows. airGP does not provide tax advice or replace an accountant.

Does airGP send invoices by email?

Yes. airGP can email generated invoice PDFs and retain invoice email logs. It can also send payment-reminder emails from the invoice workflow.

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