Key points
- Your North Star: every expense must be justifiable as a business cost (and documented).
- Travel is the #1 error zone: HMRC commuting vs business travel is where people get caught out.
- Keep a mileage log with date + route + purpose (not just ‘work’).
- If you cannot explain the expense in one calm sentence, do not claim it.
- Recordkeeping is not optional: receipts, invoices, bank entries, and logs are the whole game.
The ‘one sentence’ test
If HMRC asked, could you defend the expense in one sentence?
Example: “Indemnity subscription required to practise as a locum clinician.”
Bad example: “Laptop because I like a nicer one than work provides.”
The commuting trap (why clinicians accidentally over-claim)
Many doctors claim travel that is essentially commuting (home → usual place of work). HMRC rules distinguish normal commuting from business travel. This is a common audit trigger.
The operational fix: document why a journey is a business journey, not just that you travelled.
A defensible expense system (practical, not theoretical)
1
1) Separate bank account for locum work (if possible)
Make locum income and costs visible. Mixed accounts create mixed evidence and poor recall.
2
2) Capture receipts at source
Same day. Store digitally in one folder. Rename files with date + supplier + category.
3
3) Maintain a mileage log
Include: date, start + end points, purpose, and total miles. Keep it consistent.
4
4) Categorise costs monthly
Once per month: tag costs into categories (professional fees, travel, equipment, accountancy, phone/data, etc.).
5
5) Keep “why” notes for borderline items
For anything that could be questioned, add a one-line rationale while you remember.
High-risk categories (be conservative here)
• Travel that looks like commuting
• Dual-purpose items (part work, part personal)
• Meals that are not clearly business travel-related
If it is dual-purpose, document the business proportion and be realistic.
What to keep (minimum evidence pack)
Keep:
• Invoices + timesheets
• Bank statements showing payment/expense
• Receipts (where relevant)
• Mileage/travel log
• Any contracts/booking confirmations (for context)
Aim for ‘audit-ready by default’.
SourceGOV.UK — Self-employed expenses (official starting point)
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Make locum income and costs visible. Mixed accounts create mixed evidence and poor recall.
Return to this sectionSame day. Store digitally in one folder. Rename files with date + supplier + category.
Return to this sectionInclude: date, start + end points, purpose, and total miles. Keep it consistent.
Return to this sectionOnce per month: tag costs into categories (professional fees, travel, equipment, accountancy, phone/data, etc.).
Return to this sectionFor anything that could be questioned, add a one-line rationale while you remember.
Return to this section
Finances · Article 8 of 16