The Complete Guide to Self-Employed Expenses: Every HMRC Category Explained

One of the most straightforward ways to reduce your tax bill as a UK freelancer or sole trader is to claim every expense you are legitimately entitled to. The problem is that HMRC's own guidance can feel like it was written for accountants, not for the self-employed web designer trying to figure out whether their new laptop counts.

This guide walks through every official HMRC expense category, drawn from the Self-Employment Business API (v5.0) field structure and HMRC's published guidance, in plain language with real-world examples for each. It also explains one concept that trips up a lot of freelancers: disallowable expenses, and why some costs (or portions of costs) simply cannot reduce your tax bill, no matter how genuinely business-related they feel.

This is general guidance for educational purposes. For your specific situation, speak to a qualified accountant or tax adviser, especially for larger or more complex claims.

What "Allowable Expenses" Actually Means

Before getting into the categories, it helps to understand the rule that underpins all of this.

HMRC allows you to deduct an expense from your trading income if it was incurred "wholly and exclusively for the purposes of the trade." That phrase, wholly and exclusively, is the one to remember. It means the expense must have been for your business, full stop. If there was any personal element, you can only claim the portion that was genuinely business-related (and in some cases, you cannot claim anything at all).

Your allowable expenses reduce your profit figure. Lower profit means a lower tax bill. That is the whole point.

What Are Disallowable Expenses?

A disallowable expense is a cost that does not qualify for a tax deduction, either because it breaks the "wholly and exclusively" rule or because HMRC has a specific statutory prohibition on it.

Some expenses are entirely disallowable. Others are partly disallowable, meaning you can claim the business portion but not the personal portion. And some expenses, like the depreciation of equipment, are disallowable because HMRC has a different mechanism (capital allowances) for handling them.

You will still see disallowable figures on HMRC's Making Tax Digital (MTD) forms and in accounting software; they are tracked separately so HMRC can reconcile what went through your books against what you are actually claiming.

The HMRC Expense Categories: A Complete Breakdown

1. Cost of Goods Sold#

What it covers: The direct cost of producing or buying whatever you sell. For a freelancer who buys materials or digital assets to deliver a project, this is where those costs go.

Examples:

• A graphic designer who purchases stock imagery, fonts, or print materials for a client project
• A consultant who buys specific research reports to complete a piece of work
• A craftsperson who purchases raw materials to make products

Disallowable element: Any materials purchased but used for personal projects rather than client work. If you bought specialist software for a client job but then used it for personal side projects too, only the business-use proportion is deductible.

2. CIS Payments to Subcontractors#

What it covers: This one is specific to the construction industry. If you are a contractor registered under the Construction Industry Scheme (CIS), you can deduct the amounts you pay to subcontractors for work done on your contracts.

Examples:

• A self-employed builder who hires a plasterer to finish a project
• A sole trader electrician who brings in a subcontractor to help on a large commercial fit-out

Disallowable element: Any payments made to subcontractors for work outside your trade, or personal payments dressed up as business subcontracting.

3. Staff Costs#

What it covers: If you employ anyone, even part-time, their wages, salaries, employer's National Insurance contributions, pension contributions, and any staff-related benefits come under this category.

Examples:

• Paying a part-time virtual assistant to handle your admin
• A freelance web developer who brings in a junior developer and pays them a day rate
• Employer NI contributions for a member of staff

Disallowable element: Paying yourself a salary (sole traders cannot pay themselves a salary; any drawings you take are not an allowable expense). Payments to connected persons that are above the going market rate for the work may also face scrutiny.

4. Travel Costs#

What it covers: Travel that is wholly and exclusively for business purposes. This includes fuel, parking, public transport fares, and mileage if you use your own car.

Examples:

• Train fares to visit a client in another city
• Fuel or mileage costs when driving to a client's office
• Parking fees at a client's site
• Taxis to a business meeting

Disallowable element: Commuting costs, meaning travel from your home to a regular, permanent workplace, are not allowable. This catches people out: if you have one regular client whose office you visit every day, HMRC may treat that as a commute, not a business trip.

Also worth knowing: if you use the same car for personal and business driving, you must keep a mileage log and only claim the business-use proportion. The HMRC approved mileage rate is 45p per mile for the first 10,000 business miles per year, and 25p per mile after that.

5. Premises Running Costs#

What it covers: The cost of running a business premises: rent, business rates, utilities (heating, lighting, water), and building insurance.

Examples:

• Rent on a studio or office you use exclusively for your business
• Business rates on a commercial premises
• Electricity and heating bills for a workshop or studio

If you work from home: You can claim a proportion of your home running costs, based on the number of rooms and hours you work there. HMRC also offers a simplified flat-rate option (currently £10 per month for 25–50 hours worked from home per month, £18 per month for 51–100 hours, and £26 per month for over 100 hours).

Disallowable element: The personal portion of your home costs if you work from home. You cannot claim 100% of your mortgage or rent simply because you have a home office; only the business-use proportion counts.

6. Maintenance Costs#

What it covers: Repairs and maintenance to business property or equipment. This covers keeping things in good working order, not improving or upgrading them.

Examples:

• Getting a broken studio heating system repaired
• Fixing a client-facing website bug on a server you own
• Repairing a camera used for professional photography work

The repair vs improvement distinction: Repairing a leaky roof is allowable; replacing it with a brand-new, better roof is a capital improvement and treated differently. Patching a machine is allowable; replacing it with a newer model is not a repair.

Disallowable element: Improvements and upgrades to assets are capital expenditure, not repairs, and are handled through capital allowances rather than as a direct expense deduction.

7. Admin Costs#

What it covers: The day-to-day costs of running your business from an administrative standpoint. Stationery, postage, printing, office supplies, phone bills, broadband, and software subscriptions all fall here.

Examples:

• Your business phone contract or the business proportion of a personal phone contract
• Subscriptions to tools like project management software, cloud storage, or invoicing software
• Stationery, printer ink, and postage for sending client documents
• Home broadband costs (business proportion)

Disallowable element: Where a phone or broadband plan is shared between personal and business use, only the business proportion is allowable. HMRC expects you to make a reasonable estimate of the split. Using your entire phone bill when you also use it for personal calls is not acceptable.

8. Business Entertainment Costs#

What it covers: This category exists on HMRC's forms, but it is almost entirely disallowable, which is why it is worth understanding clearly.

Business entertainment (taking a client out for dinner, buying drinks at a networking event, or treating prospects to hospitality) is specifically prohibited as a tax deduction under UK tax law, even when it is a genuine and necessary part of winning or maintaining business.

What IS allowable:

• Entertaining your own employees (staff parties and events, subject to rules)
• Costs of hospitality where your business sells entertainment as part of its trade
• Advertising to the general public (a branded stand at a trade show, for example)

What is disallowable (the common cases):

• Taking a client to lunch to discuss a project
• Buying a round of drinks at a client meeting
• Corporate hospitality at sporting events
• Gifts to clients (except small branded items worth under £50 per person per year that are not food, drink, or tobacco)

Disallowable element: For most freelancers and sole traders, the entire entertainment and client gift budget is disallowable. This is one of the most common misconceptions: the idea that because you did it for business, it must be deductible. The law specifically says it is not.

9. Advertising Costs#

What it covers: All legitimate marketing and advertising spend to promote your business.

Examples:

• Google or social media advertising campaigns
• Your business website design and hosting costs
• Printing business cards or leaflets
• Listing fees on freelance platforms or directories
• Sponsorship of an event (where the primary purpose is advertising your business publicly, not entertaining specific clients)

Disallowable element: Advertising spend that blurs into entertainment (for example, sponsoring a box at a football stadium and filling it with clients) may be treated as business entertainment and disallowed.

10. Interest on Bank and Other Loans#

What it covers: The interest element of business loans, overdrafts, and other financing specifically taken out for your business.

Examples:

• Interest on a business overdraft used to cover cash flow gaps
• Interest charges on a business loan taken to buy equipment
• Interest on a credit card used exclusively for business purchases

Disallowable element: The capital repayment portion of a loan is not an allowable expense; only the interest is. And if a loan is partly personal and partly business, only the interest attributable to the business portion is deductible.

11. Finance Charges#

What it covers: Other financial costs related to your business that are not covered by the loan interest category. This includes bank charges, payment processing fees, and lease finance costs.

Examples:

• Monthly business bank account fees
• Payment processing fees from Stripe, PayPal, or similar services
• Foreign currency transaction fees on international client payments
• Finance charges on a hire purchase agreement for business equipment

Disallowable element: Personal bank charges or fees on accounts used for both personal and business purposes must be apportioned.

12. Irrecoverable Debts (Bad Debts)#

What it covers: If a client genuinely cannot or will not pay an invoice, and you have taken reasonable steps to recover the money, you may be able to deduct that bad debt as a business expense.

Examples:

• A client goes into insolvency and you receive nothing from the administrator
• A client disappears and debt collection efforts have been exhausted
• An invoice that has been formally written off after reasonable recovery attempts

Important caveat: This only applies if you use accruals basis accounting (where you record income when you invoice, not when you receive payment). If you use cash basis accounting, which many freelancers do and which HMRC now recommends as the default, you never recorded the unpaid invoice as income in the first place, so there is nothing to write off.

Disallowable element: Provisions for debts that might go bad (but have not actually done so) are disallowable. HMRC only accepts a deduction once a specific debt has been identified as genuinely irrecoverable.

13. Professional Fees#

What it covers: Fees paid to accountants, solicitors, and other professional advisers for work directly related to your business.

Examples:

• Your accountant's fee for preparing your Self Assessment tax return
• A solicitor's fee for drafting a client contract
• Professional indemnity insurance premiums
• Membership fees for a professional body relevant to your trade

Disallowable element: Legal or professional fees relating to capital transactions (for example, a solicitor's cost for buying a business premises) are capital in nature and not deductible as a revenue expense. Legal costs for personal matters, even if they indirectly affect your business, are also disallowable.

14. Depreciation#

What it covers: In an accounting sense, depreciation is how businesses gradually write off the cost of long-lived assets (equipment, vehicles, machinery) over their useful life.

Why it is disallowable: Depreciation is entirely disallowable for tax purposes. This is not because HMRC is being unkind; the tax system has its own version of the same concept: capital allowances. Rather than letting each business choose its own depreciation method, HMRC sets standard rates at which you can deduct the cost of assets.

Capital allowances instead:

• Annual Investment Allowance (AIA): Deduct the full cost of most plant and machinery up to £1 million in the year you buy it
• Writing Down Allowances: Deduct 18% per year (main rate) or 6% per year (special rate for cars, long-life assets) on items not covered by the AIA

If you are using cash basis accounting, capital allowances only apply to cars; all other equipment costs can be deducted directly in the year of purchase.

15. Other Expenses#

What it covers: The catch-all category for legitimate business expenses that do not fit neatly into any other category.

Examples:

• Professional development courses and training directly relevant to your current trade (refresher courses and skills updates, but not training to qualify in a new profession)
• Industry magazine subscriptions
• Trade body membership fees
• Health and safety equipment required for your work

Disallowable element: Training costs to enter a new profession or to qualify for the first time are capital in nature and are not allowable. HMRC's position is that you can claim for maintaining and updating skills, not for acquiring an entirely new set of them.

A Quick Summary: What Is and Is Not Allowable

Expense	Allowable?
Business travel (client visits, meetings)	Yes
Commuting to a regular workplace	No
Home office costs (proportion)	Yes
Client entertainment (meals, drinks)	No
Staff wages and employer NI	Yes
Drawings/salary paid to yourself	No
Business loan interest	Yes
Loan capital repayments	No
Professional fees (accountant, solicitor)	Yes
Legal fees on capital transactions	No
Bad debts (accruals basis, genuine write-offs)	Yes
Depreciation of assets	No (use capital allowances)
Advertising and marketing	Yes
Client gifts over £50 per person	No
Training to maintain current skills	Yes
Training to enter a new profession	No

A Note on Cash Basis vs Accruals Basis

Most sole traders and freelancers use cash basis accounting, which HMRC now makes the default for unincorporated businesses. Under cash basis, you record income when you receive it and expenses when you pay them. This simplifies bookkeeping considerably.

A few rules differ under each method, particularly around bad debts and how stock is valued, so if you are unsure which method you are using or should be using, your accountant can advise.

Keeping Records That Stand Up

HMRC can open an enquiry into your tax return for up to four years after submission (and longer if there is suspected fraud). That means you should keep:

• Receipts and invoices for every expense you claim
• Bank statements that match those receipts
• A mileage log if you claim travel in your own vehicle
• Records of any business-use calculations for mixed-use expenses (phone, broadband, home office)

You do not need to send these to HMRC when you file, but you need to be able to produce them if asked.

Track Your Expenses Without the Spreadsheet Chaos

Knowing which categories apply is only half the battle. The other half is actually recording your expenses consistently throughout the year, so you are not scrambling for receipts every January.

Qazua's expenses module lets you log and categorise business expenses against the correct HMRC categories as you go, so your records are already organised when Self Assessment comes around. Combined with invoicing that keeps your income records equally tidy, it means less time on admin and a cleaner picture of your business finances.

Try Qazua free for 14 days. No credit card required.

Summary

• HMRC allows expenses that are "wholly and exclusively" for the purposes of your trade. Mixed personal and business expenses must be apportioned.
• Disallowable expenses are costs (or portions of costs) that cannot reduce your taxable profit, either because of the "wholly and exclusively" rule or because a specific statutory prohibition applies.
• Business entertainment is almost entirely disallowable, even when it is genuinely business-related.
• Depreciation is disallowable because capital allowances do the same job in a standardised way. Use the Annual Investment Allowance for most equipment.
• Keep records of every claim; HMRC can enquire into returns for up to four years.

Important disclaimer: This article provides general information and is not financial or tax advice. Tax rules can be complex and vary based on individual circumstances. For specific advice about your situation, consult a qualified accountant or tax adviser. Always check gov.uk for the most up-to-date official information.