What are the Tax Implications of Going Self-Employed?

Going self-employed brings freedom — and a completely different tax life. No employer deducts tax for you; instead you report your own profits, calculate your own bill, and pay it in large instalments. Understand the implications before you start, and you will avoid the cash-flow shocks that catch out so many new freelancers.

Need help with your Self Assessment Tax Return? Let us make it simple for you.

Registering as Self-Employed

You must register with HMRC if your self-employed income exceeds £1,000 in a tax year (the trading allowance). The deadline is 5 October following the end of the tax year in which you started trading — so if you started in 2026/27, register by 5 October 2027. You can register for Self Assessment online on GOV.UK; HMRC will send you a Unique Taxpayer Reference (UTR).

What Are the Tax Implications of Going Self-Employed?

Unlike employees, who pay tax automatically through PAYE, you are responsible for working out and paying your own tax. The two main charges are Income Tax and National Insurance, both calculated on your taxable profit (income minus allowable expenses).

Income Tax on Your Profits

For 2026/27 the bands are:

• Personal Allowance: no tax on the first £12,570 of profit
• Basic rate (20%): £12,571 to £50,270
• Higher rate (40%): £50,271 to £125,140
• Additional rate (45%): above £125,140

Worked example: on £30,000 of profit, Income Tax is 20% × (£30,000 − £12,570) = £3,486.

National Insurance Contributions (NICs)

You must pay National Insurance as a self-employed person. For 2026/27:

• Class 4 NICs: 6% on profits between £12,570 and £50,270, then 2% above £50,270. On £30,000 of profit that is 6% × £17,430 = £1,045.80. See the current self-employed NI rates on GOV.UK.
• Class 2 NICs: compulsory Class 2 was abolished in April 2024. Profits of at least £7,105 a year are now automatically treated as paid, protecting your State Pension record. You can pay voluntary Class 2 at £3.65 a week to fill gaps.

Total bill on £30,000 profit: £3,486 + £1,045.80 = £4,531.80.

Claiming Allowable Expenses

Self-employed expenses reduce your taxable profit — and therefore your bill. Common claims include:

• Home office costs: a proportion of rent, utilities, council tax and broadband
• Office supplies: stationery, ink, software and equipment
• Business travel: mileage at 45p per mile (first 10,000 miles), parking, trains and hotels
• Marketing and advertising: websites, hosting and online ads
• Professional fees: accountants, solicitors and business consultants

Every £1,000 of expenses saves a basic-rate taxpayer £200 in Income Tax plus £60 in Class 4 NI. Learn how to plan for your self-employed tax bill so the January payment never surprises you.

VAT Considerations

You must register for VAT once your VAT-taxable turnover exceeds £90,000 in any rolling 12-month period. Registration means charging VAT on your sales and filing VAT returns — but you can also reclaim VAT on business purchases. Voluntary registration can suit businesses selling mainly to VAT-registered customers.

Payments on Account

This is the shock that catches new freelancers out. If your tax bill exceeds £1,000, HMRC collects payments on account — advance payments towards next year’s bill:

• 31 January: your balancing payment plus 50% of the bill as a first payment on account
• 31 July: the second 50%

Example: with a £4,531.80 bill, your first January payment is £4,531.80 + £2,265.90 = £6,797.70. Budget for this from month one — see the Self Assessment return filing deadlines.

Maintaining Financial Records

Keep records of all income and expenses — invoices, receipts, bank statements — for at least six years after the end of the tax year. Digital bookkeeping or accounting software makes this painless and gives you real-time visibility of your profit and likely tax bill.

How to File Your Self-Assessment Tax Return

Each year you must file online by 31 January:

• Collect records: income, expenses, invoices and receipts
• Calculate taxable profit: income minus allowable expenses
• Complete the return: enter earnings, expenses and reliefs
• Submit and pay: file online and pay by 31 January to avoid the automatic £100 penalty

Read our full guide on how to file your Self Assessment tax return.

Frequently Asked Questions

How much tax will I pay as a new freelancer?

Profits above £12,570 are taxed at 20%, 40% or 45%, plus Class 4 NI of 6% between £12,570 and £50,270 (2% above). On £30,000 of profit the combined bill is £4,531.80.

When do I first pay tax?

Your first payment is due by 31 January after the tax year ends. If the bill exceeds £1,000 you will also pay payments on account — so budget for roughly 150% of your first bill in January.

Do I still pay National Insurance?

Yes — Class 4 NICs on profits, collected through Self Assessment. Compulsory Class 2 was abolished in 2024; profits over £7,105 now protect your State Pension automatically.

Can I be employed and self-employed at the same time?

Yes. You pay PAYE on your salary and Self Assessment on your freelance profits. The two are combined to work out your total tax.

What records do I need to keep?

All sales invoices, expense receipts, bank statements and mileage logs — kept for at least six years. Good records maximise your expense claims and protect you in an HMRC enquiry.

Related Guides

• How to Register for Self Assessment as a Sole Trader
• Allowable Expenses for the Self-Employed: Full Guide
• Sole Trader vs Self-Employed: What Is the Difference?

Conclusion

Going self-employed means swapping PAYE simplicity for control — and responsibility. Register on time, track every expense, set aside 25–30% of profit for tax, and never underestimate payments on account. Get those habits right and the tax side of freelancing becomes routine rather than stressful. If you would rather a professional handled it all, our accountants prepare and file your Self Assessment for a fixed fee from £199 + VAT — contact our team today.