Do I need to register before sending my first invoice?

You do not usually need a UTR before physically sending an invoice, but you must register for Self Assessment by the HMRC deadline if you need to send a tax return.

What is the registration deadline?

GOV.UK says you must tell HMRC by 5 October after the tax year if you need to complete a tax return and have not sent one before, or need to reactivate.

What should be on a first invoice?

Include your name or trading name, client details, invoice date, description, amount, payment terms and records that support the work.

Do I need to register self-employed before my first invoice?

Last reviewed: 15 June 2026

Quick summary

You usually do not need to wait for a UTR before sending a first invoice, but you do need to register by the HMRC deadline if Self Assessment is required.
GOV.UK says you must tell HMRC by 5 October after the tax year if you need to complete a tax return and have not sent one before.
Keep invoice, payment, expense and client records from day one, even if income stays below the £1,000 trading allowance.

Topic hub: Side hustle tax guides

Direct answer

You do not normally need to be registered with HMRC before you physically send your first invoice as a sole trader. However, if you need to complete a Self Assessment tax return, GOV.UK says you must tell HMRC by 5 October after the tax year, if you have not sent a return before or need to reactivate your account.

The bigger risk is not the first invoice itself. It is forgetting the tax year, losing records, crossing the £1,000 trading allowance point, or assuming "not registered yet" means the income does not count. The income exists when you earn it, and the records should start immediately.

The first-invoice timeline

Step one is agreeing the work and price. Step two is creating a clear invoice with your name or trading name, client name, invoice date, description, amount and payment details. Step three is recording the payment and any expenses. Step four is checking the tax year total and whether Self Assessment registration is needed.

GOV.UK's registration deadline is not "before first invoice"; it is tied to needing a tax return for the previous tax year. That gives new side hustlers breathing room, but it is not a reason to delay records. Competitor articles often either scare people into thinking they cannot invoice without a UTR, or make registration sound optional admin. A better answer separates commercial invoicing, tax registration, banking, VAT and record keeping.

If a client asks for your UTR, remember that a UTR is personal tax information. Ask why they need it. Some clients simply need an invoice; others may have specific compliance checks.

Examples

You invoice £300 for a one-off logo. You may not need immediate registration, but keep the invoice and payment record.
You invoice £1,500 for website work while employed PAYE. Check Self Assessment because the amount is over the £1,000 point before expenses.
You send three invoices in March and get paid in April. Dates matter because tax years run to 5 April.
You buy software before the first sale. Keep startup cost records in case the business becomes reportable.
You expect sales to grow quickly. Ask about VAT, MTD and whether sole trader or company setup needs reviewing.

Records to gather from the first invoice

Invoice number, date, client, work description and amount.
Payment date and bank or payment processor evidence.
Messages, proposal, scope or contract.
Expenses paid before and after the first invoice.
Tax year totals and whether income crosses £1,000 before expenses.
PAYE income if you also have a job.
Whether you have registered before and need to reactivate Self Assessment.
Whether the client expects you to be sole trader, company or VAT registered.

Common mistakes

The first mistake is waiting for a UTR before doing any paid work, when the real issue is meeting HMRC deadlines and keeping records. The second is sending invoices but not saving them. The third is assuming the trading allowance means no records are needed. GOV.UK says if you use the allowance, you must still keep a record of income.

The fourth mistake is confusing tax registration with business banking. Your tax position is one issue; whether your personal bank allows business use is another. If the work will continue, a separate account can make records easier, even if it is not what makes the income taxable.

What to write in your first accountant message

Try: "I am about to send my first sole-trader invoice. The amount is this, the client is this type, and I also have PAYE income. I need to know whether I should register now or by 5 October, what records to keep, and whether the trading allowance or expenses route is better." Attach the draft invoice and expected expenses.

What your first invoice should make clear

Your first invoice should be boringly clear. Include invoice date, invoice number, your name or trading name, client name, description of the work, amount charged, payment details and payment terms. If you are not VAT registered, do not add VAT. Keep the invoice even if the client pays immediately, because the invoice explains what the bank receipt was for.

You do not need to over-brand the invoice or pretend to be bigger than you are. The important part is that the client, amount and work are clear. If you later register for Self Assessment, open a business account or hire an accountant, this first invoice becomes part of the record trail. If you later decide the work was a one-off and covered by an allowance, the invoice still proves what happened.

When to register earlier anyway

You might register earlier if you know you will cross the threshold, want voluntary Class 2 National Insurance considered, need a UTR for a legitimate client onboarding process, have previous Self Assessment history to reactivate, or simply want the admin done well before the 5 October deadline.

Questions to ask an accountant

Do I need to register for Self Assessment for this tax year?
What exact 5 October deadline applies to me?
Can I invoice as an individual or trading name?
Should I use the trading allowance or track actual expenses?
Should I think about VAT, MTD or a limited company if more work follows?

Key takeaway

You do not usually need to wait for HMRC registration before sending the first invoice, but you do need a clean record trail and a calendar reminder for the Self Assessment deadline.

Official guidance checked on 15 June 2026

FAQs

Can I invoice without a UTR?

Usually yes for ordinary sole-trader invoicing, but you still need to register by the HMRC deadline if a tax return is required.

Do I need a business bank account first?

Tax and banking are separate issues. A separate account can help records, but the income can still be taxable either way.

What if I stay under £1,000?

You may be covered by the allowance depending on the facts, but GOV.UK says you should still keep income records.