Going self-employed: the first five things.

1. Register as self-employed with HMRC

If you earn more than £1,000 in a tax year from self-employment, you need to register with HMRC for Self Assessment. The tax year runs from 6 April to 5 April, and the deadline to register is 5 October following the end of the tax year in which you started. Registering early costs nothing and avoids a penalty.

You can work while your registration is processing. Most people register as a sole trader, which is the simplest structure: you and the business are the same legal entity, you keep the profit and you are personally responsible for any debts.

2. Your UTR number

After you register, HMRC issues a Unique Taxpayer Reference — a 10-digit number that identifies you for tax. It arrives by post, and it also appears in your HMRC online account and on Self Assessment correspondence. It usually takes a couple of weeks, so do not leave it until January.

You will need it to file a return, and platforms and agencies often ask for it to confirm you are registered. Treat it like a bank detail: it is not secret in the way a password is, but there is no reason to post it publicly.

3. Insurance

Public liability insurance covers injury to a client or damage to their property while you are working. It is not a legal requirement for most trades, but almost every platform, agency and sensible client expects it, and one broken laptop or water leak costs more than years of premiums. £1m to £5m of cover is the usual range quoted.

Depending on what you do you may also need treatment or professional indemnity cover for beauty and therapy work, tools cover, and employers' liability if you ever take someone on — that one is a legal requirement. Check that your policy actually names the treatments or services you offer; a generic policy often excludes specific ones.

4. Setting your first prices

The most common mistake is copying someone else's hourly rate and forgetting that it is not take-home pay. Work backwards instead.

• ·Decide what you want to earn in a year after costs
• ·Subtract nothing you will not actually be paid for: holidays, sickness, admin, travel between jobs
• ·Count realistic billable hours — for most mobile services that is 20 to 25 a week, not 40
• ·Add your costs: products, equipment, travel, insurance, phone, replacing tools
• ·Set aside roughly 20 to 30 per cent of profit for tax and National Insurance
• ·Compare the result with local rates, then adjust for your experience — not the other way round

5. Records, invoices and tax

Keep records of everything you earn and spend from day one, and keep them for at least five years after the filing deadline. A separate bank account is not legally required for sole traders but makes this vastly easier.

Track allowable expenses as you go — equipment, products, insurance, professional subscriptions, mileage or travel for work, and a proportion of phone and home costs if you work from home. These reduce the profit you pay tax on, but only if you have the records.

Your first Self Assessment return is due by 31 January after the end of the tax year, with tax owed due the same day. If your bill is over a threshold, HMRC will also ask for payments on account towards next year — a genuine surprise for many people in their second January, so plan for it.

Practical things people wish they had done sooner

Open a separate account and move the tax percentage into it every time you get paid. Write down your cancellation and travel policy before your first awkward client rather than after. Ask for reviews immediately after a job while people are happy. And do not undercharge to get started — raising a price with an existing client is far harder than setting it correctly on day one.