How to Invoice as a Sole Trader in the UK (2026 Guide)

As a sole trader, every invoice you send must include: your name and any business name you trade under, an address where legal documents can be delivered, the customer's name and address, a unique identifying invoice number, the invoice date, a clear description of the goods or services supplied, and the amount owed. If you charge for individual items or hours, show the quantity and price of each.

Unlike a limited company, you don't have a company registration number, but you must show your own name alongside any trading name. So if you trade as 'Brightspark Electrical', your invoice should read something like 'Jane Smith, trading as Brightspark Electrical'. If you're VAT registered, extra rules apply—your VAT number and a VAT breakdown become mandatory (more on that in our UK VAT invoice requirements guide).

HMRC expects invoice numbers to be unique and, if you're VAT registered, sequential. Even if you're not VAT registered, sequential numbering is the sensible habit: it keeps your records audit-ready and makes missing invoices easy to spot.

A simple format works best. Start at INV-001 and count up, or use a year prefix like 2026-014 so each tax year starts fresh. Whatever you choose, never reuse a number and never leave gaps you can't explain. If you cancel an invoice, keep a copy and issue a credit note rather than deleting it. Invoicing software handles this for you automatically—ZeroDue assigns the next number in sequence every time, so you never send a duplicate.

Say Jane rewires a kitchen over three days. Her invoice might look like this. Header: 'Jane Smith, trading as Brightspark Electrical', her address and contact details, the client's name and address, invoice number 2026-014, and the invoice date. Line items: 'Kitchen rewire — labour, 3 days at £280 per day: £840.00' and 'Materials — cable, sockets, consumer unit parts: £145.50'. Total due: £985.50.

Below the total she adds payment terms ('Payment due within 14 days by bank transfer'), her sort code and account number, and a short thank-you line. Because Jane isn't VAT registered, she charges no VAT and doesn't mention it. That's a complete, legally compliant sole trader invoice—nothing more is required.

You're free to set your own payment terms, but if you don't agree any, the law assumes 30 days for business customers. Most sole traders do better with shorter terms: 7 or 14 days is common and perfectly reasonable for small jobs.

State the due date as an actual date ('Due by 6 August 2026') rather than only 'Net 14'—clients respond better to concrete dates. Include your bank details on the invoice itself so nobody has to email you to ask. And remember that if a business client pays late, you're legally entitled to statutory interest at 8% plus the Bank of England base rate, plus fixed compensation—see our guide to chasing unpaid invoices for how that works.

Keep copies of every invoice you send, along with receipts, bank statements, and expense records. As a sole trader you must keep records for at least 5 years after the 31 January submission deadline of the relevant tax year. So records supporting your 2025-26 return need to survive until at least 31 January 2032.

Digital records are fine, and increasingly expected: Making Tax Digital for Income Tax began rolling out in April 2026 for sole traders with qualifying income over £50,000, which means keeping digital records and sending quarterly updates to HMRC. Storing invoices in software rather than a shoebox stops this being a headache. Every invoice you create in ZeroDue is saved, numbered, and searchable automatically.

You have three options: build a template in Word or Excel, use a free online tool, or use dedicated invoicing software. A template works for your very first invoice, but you'll quickly find yourself copying files, fixing numbering, and forgetting who has paid.

For a quick start, the free invoice generator at zerodue.co/tools/invoice-generator lets you create a professional, compliant invoice in a couple of minutes with no account needed. If you invoice regularly, a ZeroDue account adds automatic numbering, client records, payment tracking, and reminders that chase late payers for you. There are also tailored pages for specific trades—see zerodue.co/industries/electricians, zerodue.co/industries/plumbers, and zerodue.co/industries/freelancers for examples relevant to your work.

Do I need to register anywhere before I can invoice? No. You can invoice as soon as you start trading. You do need to register with HMRC for Self Assessment—by 5 October following the end of your first tax year at the latest—but that's separate from invoicing.

Do sole traders charge VAT? Only if VAT registered. Registration is compulsory once your taxable turnover passes the VAT threshold (£90,000 at the time of writing—check GOV.UK for the current figure). Below that, don't charge VAT and don't mention a VAT rate on invoices.

Can I invoice without a business bank account? Legally, yes—sole traders can use a personal account. In practice, a separate account makes record keeping and tax returns far easier.

What if I make a mistake on an invoice I've sent? Don't delete it. Issue a credit note for the wrong invoice and send a corrected one with a new number, keeping copies of all three.

Good invoicing habits cost nothing to set up and save real money in unpaid bills and tax-season stress. Include the required details, number invoices sequentially, keep every copy, and set clear payment terms. If you'd rather not manage that manually, try ZeroDue free—create your first professional invoice in under five minutes, and let automatic reminders handle the chasing.