Tax as a sole trader: the basics
As a sole trader, you pay two taxes on your business profits: income tax and Class 4 National Insurance. Both are calculated on your annual profit — your income minus allowable business expenses — and reported through a Self Assessment tax return filed each year.
| Tax | Rate | Applies on profits between |
|---|---|---|
| Income tax (basic rate) | 20% | £12,571 – £50,270 |
| Income tax (higher rate) | 40% | £50,271 – £125,140 |
| Income tax (additional rate) | 45% | Above £125,140 |
| Class 4 NI | 6% | £12,570 – £50,270 |
| Class 4 NI (upper) | 2% | Above £50,270 |
The personal allowance (£12,570) is your tax-free amount. If your total income from all sources — including any employed income or interest — exceeds £100,000, the personal allowance tapers by £1 for every £2 over that threshold and disappears completely at £125,140.
Self Assessment: key dates
- 5 October: Register for Self Assessment if newly self-employed
- 31 October: Deadline for paper tax returns
- 31 January: Deadline for online tax returns and payment of any tax owed, plus first payment on account for next year
- 31 July: Second payment on account
Payments on account: If your Self Assessment bill exceeds £1,000, HMRC requires advance payments toward next year's bill — 50% on 31 January and 50% on 31 July. In your first year, you pay your current tax bill plus the first payment on account in January. Budget for this from the start — it catches many new freelancers off guard.
What expenses can you deduct?
Allowable expenses reduce your taxable profit. They must be "wholly and exclusively" for business use. Common deductions include:
- Office rent, or a proportion of home costs if working from home (the simplified flat-rate method is £10–£26/month depending on hours)
- Equipment and software — capital items can be fully expensed in the year of purchase via the Annual Investment Allowance
- Business travel (mileage at 45p/mile for the first 10,000 miles, 25p thereafter)
- Professional subscriptions and trade memberships
- Marketing and advertising costs
- Accountancy and professional fees
- Relevant training and development directly related to your current trade
- Business insurance premiums
You cannot deduct client entertainment, personal expenses, or training for a completely new career. The cost of buying a business asset (e.g. a van) is a capital item — it may qualify for the Annual Investment Allowance rather than being deducted as a regular expense.
Sole trader vs limited company
- Simple setup — just register with HMRC
- Annual Self Assessment return
- All profits taxed immediately as income
- Personally liable for all debts
- No corporation tax, no payroll
- Best for lower profit levels and simple businesses
- More admin: Companies House, annual accounts, payroll
- Limited liability protection
- Salary + dividends structure reduces NI
- Corporation tax on profits (19–25%)
- Can retain profits inside the company
- Better for higher profit levels (broadly £50k+)
The tax saving from a limited company comes primarily from avoiding self-employed NI on income taken as dividends instead of salary. At £50,000 profit, the saving over sole trader can be several thousand pounds — but you also incur accounting fees (typically £1,000–£3,000 per year for a small company) and spend more time on administration.
At profits below roughly £30,000–£35,000, the saving rarely justifies the cost and hassle. Above £50,000–£60,000, the case becomes stronger — particularly if you want to retain some profit in the company rather than drawing it all immediately. Use the Dividend Tax Calculator to compare salary versus dividends side by side.
National Insurance for the self-employed
Class 4 NI is charged at 6% on profits between £12,570 and £50,270, and 2% above. Unlike employed workers, you pay no employer's NI (13.8%) on top — this is one of the genuine tax advantages of self-employment, particularly at higher income levels.
Class 2 NI was effectively abolished from April 2024. If your profits exceed £6,725 (the Small Profits Threshold), you now automatically receive NI credits toward your State Pension without payment. If your profits are below this, you can pay voluntary Class 2 contributions (£3.45/week) to protect your State Pension entitlement — worth doing if you have gaps in your NI record.
VAT
VAT registration is compulsory once your taxable turnover exceeds £90,000 in any rolling 12-month period. Once registered, you:
- Charge VAT (20% standard rate, 5% reduced, 0% zero-rated) on eligible sales
- Reclaim VAT on business purchases
- Submit quarterly VAT returns and pay the difference
Voluntary registration below £90,000 can be worthwhile if you have significant VAT on purchases to reclaim, or if your clients are VAT-registered businesses (who can reclaim the VAT you charge). It is less appealing if your customers are members of the public who cannot reclaim VAT.
The Flat Rate Scheme lets eligible businesses (turnover under £150,000 excluding VAT) pay a fixed percentage of gross turnover instead of tracking VAT on every purchase. The percentage varies by trade. It reduces admin but may cost more than the standard method depending on your input VAT.
Pensions and tax relief for the self-employed
Self-employed people don't have employer pension contributions, but they do have full access to pension tax relief. Contributions to a personal pension or SIPP reduce your adjusted net income, directly cutting your tax bill. A basic rate taxpayer who contributes £800 has £1,000 in their pension (the provider claims 20% relief). A higher rate taxpayer can claim back a further 20% through Self Assessment — making the effective cost £600 for every £1,000 invested.
If your profits are in the 40% band, pension contributions are one of the most efficient ways to reduce your tax bill. If your profits approach £100,000, they can also be used to restore a tapering personal allowance — creating an effective marginal tax rate of 60% in that band that contributions directly offset.