Short answer
Self-employed expense categories work best when they mirror your tax form. In the UK that means the SA103F boxes 17 to 30, from cost of goods to other business expenses. In the US it means the Schedule C Part II lines, from advertising (line 8) to other expenses. Set them up once as categories in your receipt app and totals map straight across.
Key takeaways
- UK: SA103F has fourteen expense boxes (17–30); turnover under £90,000 can use a single total in box 31.
- US: Schedule C Part II lines run from advertising (line 8) to other expenses, with detail listed in Part V.
- Name categories after the form line so nobody re-sorts receipts at year end.
- Disallowable and personal shares still need recording — the UK form has a separate column for them.
Why match categories to the tax form
Most people start with categories that describe how they think about spending — "Coffee", "Gear", "Stuff for clients". At year end, someone then has to translate those into the boxes on the tax return, receipt by receipt. Using the form's own groupings from day one removes that step and makes the totals checkable.
- Expense category (tax)
- An expense category is a label that groups business costs of the same kind so they can be totalled and reported on the matching line of a tax return or in the matching account of a set of books.
UK: SA103F expense boxes
The full self-employment pages (SA103F) list these allowable expense boxes, each with a matching disallowable box (32–45) for amounts included that you cannot claim[1]. If your annual turnover was below £90,000 you may just put total expenses in box 31[1].
| Box | HMRC label | Typical receipts |
|---|---|---|
| 17 | Cost of goods bought for resale or goods used | Stock, raw materials, materials used on jobs |
| 18 | Construction industry – payments to subcontractors | Subcontractor invoices under CIS |
| 19 | Wages, salaries and other staff costs | Payroll, staff training, temp agency invoices |
| 20 | Car, van and travel expenses | Fuel, parking, train and bus fares, hotels on business trips |
| 21 | Rent, rates, power and insurance costs | Workshop rent, business rates, business insurance |
| 22 | Repairs and maintenance of property and equipment | Tool repairs, equipment servicing |
| 23 | Phone, fax, stationery and other office costs | Phone and broadband (business share), printer ink, postage |
| 24 | Advertising and business entertainment costs | Website, ads, flyers (entertainment is usually disallowable) |
| 25 | Interest on bank and other loans | Business loan interest |
| 26 | Bank, credit card and other financial charges | Card fees, bank charges, payment processing fees |
| 27 | Irrecoverable debts written off | Invoices you will never be paid |
| 28 | Accountancy, legal and other professional fees | Accountant, solicitor, professional body fees |
| 29 | Depreciation and loss or profit on sale of assets | Accounting entries — not usually a receipt; claim via capital allowances |
| 30 | Other business expenses | Trade subscriptions, training, anything not above |
Remember mixed use: only the business share of a cost such as a phone bill is allowable[2]. Record the full receipt and note the business percentage. UK sole traders should also read the sole trader expense tracker and UK VAT receipts.
US: Schedule C expense lines
Sole proprietors report expenses in Part II of Schedule C. The lines below are from the IRS instructions[3]; items that do not fit go under other expenses, itemised in Part V.
| Line | IRS name | Typical receipts |
|---|---|---|
| 8 | Advertising | Ads, business cards, website promotion |
| 9 | Car and truck expenses | Actual costs or standard mileage — keep a mileage log either way |
| 10 | Commissions and fees | Platform and referral fees |
| 11 | Contract labor | Payments to independent contractors |
| 13 | Depreciation and section 179 expense | Equipment and machinery (via Form 4562) |
| 15 | Insurance (other than health) | Business liability, equipment cover |
| 16a / 16b | Interest (mortgage / other) | Business loan and card interest |
| 17 | Legal and professional services | Accountant, attorney, tax preparer |
| 18 | Office expense | Postage, small office items |
| 20a / 20b | Rent or lease (vehicles, machinery, equipment / other business property) | Equipment hire, office or workshop rent |
| 21 | Repairs and maintenance | Equipment and premises repairs |
| 22 | Supplies | Materials and supplies used in the business |
| 23 | Taxes and licenses | Business licences, certain business taxes |
| 24a / 24b | Travel / deductible meals | Airfare, hotels, business meals |
| 25 | Utilities | Business premises utilities, business phone |
| 26 | Wages | Employee wages (not your own draw) |
| 27b | Other expenses (from Part V, line 48) | Software subscriptions, education, bank fees and anything not above |
A starter set that works in both countries
If you are not sure yet, or you file in more than one country, start with these ten and split later. Each maps cleanly to one UK box and one US line.
| Category | UK box | US line |
|---|---|---|
| Materials & stock | 17 | 22 (or cost of goods sold, Part III) |
| Subcontractors | 18 | 11 |
| Travel & vehicle | 20 | 9 / 24a |
| Premises & insurance | 21 | 15 / 20b / 25 |
| Repairs | 22 | 21 |
| Phone, office & software | 23 / 30 | 18 / 27b |
| Advertising | 24 | 8 |
| Bank & card fees | 26 | 27b |
| Professional fees | 28 | 17 |
| Meals (business) | 20 or disallowable | 24b |
Setting these up in NexaLink Scanner
NexaLink Scanner starts with five default categories on Free. On Pro you can create custom categories — name them with the box or line number, such as "23 Office & phone" or "L22 Supplies", so the year-end report reads like the form. Use projects for clients or jobs and tags for things like "rebill" or "mixed use", so the category stays purely a tax label.
At year end, set the review period to your tax year and read the totals per category, then export a CSV (free) for your accountant or tax software. For Australia, India and Singapore, the same approach works with your local form's labels — see the tax receipts hub.
Key facts about NexaLink Scanner
- What it is: NexaLink Scanner is a private receipt and expense organiser for iOS and Android, built for freelancers, sole traders, contractors and small businesses. It is not accounting software and does not file tax returns.
- How it reads receipts: text is read on the phone (on-device OCR) and capture works offline. Merchant, date, total and tax are filled in; any value it is unsure of is flagged, and a low-confidence total cannot be saved until you confirm it.
- Where data lives: receipts are stored on your phone and do not sync to the web. Data leaves only when you export it.
- Free plan: 50 receipts, on-device reading, search, 5 default categories and CSV export. CSV export is free on every plan, always.
- Pro: $4.99 a month or $39.99 a year — unlimited receipts, custom categories, projects and tags, a PDF expense report in the app, tax and multi-currency reports. Image ZIP export and Xero / QuickBooks import files are coming soon.
- Accounting connections (none live yet): Xero — First · V1.1 · QuickBooks Online — Next · V1.2 · FreeAgent — Planned · Sage Accounting — Planned · Zoho Books — Planned · TallyPrime — Import file first. CSV export works with any accounting tool today. Status as of 2026-11-10; see accounting integrations.
Frequently asked questions
What are the main self-employed expense categories in the UK?
The SA103F self-employment pages use fourteen expense boxes: cost of goods, CIS subcontractors, staff, car/van/travel, premises, repairs, office costs, advertising, interest, financial charges, bad debts, professional fees, depreciation and other expenses. Under £90,000 turnover, you can report a single total.
What expense categories are on Schedule C?
Part II of Schedule C lists advertising, car and truck expenses, commissions and fees, contract labor, depletion, depreciation, employee benefits, insurance, interest, legal and professional services, office expense, pension plans, rent or lease, repairs, supplies, taxes and licenses, travel and meals, utilities, wages and other expenses.
Where do software subscriptions go?
In the UK they usually go in box 23 (office costs) or box 30 (other business expenses). On Schedule C they are commonly listed under other expenses in Part V. Pick one and use it consistently, and confirm with your accountant.
Should I create a category for personal spending?
Ideally keep personal spending out of your business records altogether. If a receipt is mixed — a phone bill, a meal on a trip — record it in the business category with a note of the business share rather than inventing a personal category.
Can I use the same categories in the UK and the US?
Mostly yes. The starter set on this page maps to one UK box and one US line each. The big differences are meals and entertainment, which the two systems treat very differently. Capital items such as equipment and vehicles also need care, because allowances and depreciation rules differ.
How many categories should a sole trader have?
Enough to match your tax form and no more — usually eight to fifteen. Too many and receipts get filed inconsistently; too few and you re-sort at year end. If one category ends up holding most of your spending, split it; if a category stays empty all year, remove it. Review the list once a year.
Does NexaLink set the categories up for me?
Free includes five default categories. Custom categories, which you need to mirror the SA103 or Schedule C lists, are on Pro at $4.99 a month or $39.99 a year. You create them once, naming each after the box or line it feeds, and the year-end review then lists totals in the same order as your form.
Sources
- GOV.UK — Self Assessment: Self-employment (full) (SA103F) form and notes — checked on 2026-11-10
- GOV.UK — Expenses if you're self-employed — checked on 2026-11-10
- IRS — Instructions for Schedule C (Form 1040) — checked on 2026-11-10
- IRS — Publication 463, Travel, Gift, and Car Expenses — checked on 2026-11-10