UK Sole Trader Invoicing Requirements

Sole trader invoicing basics

Operating as a sole trader is the simplest business structure in the UK. You are personally responsible for your business, and your income is taxed through Self Assessment rather than through a company. Most freelancers, consultants, and tradespeople start out as sole traders because the setup is straightforward: you register with HMRC for Self Assessment, and you are ready to start trading.

Invoicing as a sole trader does not require any special software or formal registration beyond your HMRC Self Assessment registration. However, your invoices must contain certain information, and you must keep records of all your income and expenditure for at least five years after the relevant Self Assessment deadline.

What must appear on a sole trader invoice

HMRC sets out minimum requirements for business invoices. For sole traders who are not VAT-registered, the required fields are:

• Your full legal name, or your trading name (but if you use a trading name, your legal name must also appear somewhere on the invoice)
• A business address (this can be your home address if you work from home)
• The date of the invoice
• A unique invoice number (sequential, not reused)
• The name and address of the customer
• A clear description of the goods or services supplied
• The amount charged for each item or service
• The total amount due
• Payment terms (e.g. "Payment due within 30 days")

There is no legal requirement to include a UTR (Unique Taxpayer Reference) on invoices, although some clients may request it. You do not need a company registration number because sole traders are not registered at Companies House.

VAT registration for sole traders

If your taxable turnover in the previous 12 months exceeds the VAT registration threshold (£90,000 for the 2024-25 tax year), you must register for VAT with HMRC. Taxable turnover means the total value of all VAT-taxable goods and services you supply, not just your profit.

You must also register if you expect your turnover to exceed the threshold within the next 30 days alone (for example, if you have just won a large contract). HMRC must be notified within 30 days of the date you exceeded, or expected to exceed, the threshold.

Voluntary registration below the threshold is also available. This can be useful if you supply primarily to VAT-registered businesses, because they can reclaim the VAT you charge them. Voluntary registration also allows you to reclaim input VAT on your own purchases. However, it adds administrative complexity and means you must comply with Making Tax Digital for VAT from the date of registration.

Invoicing requirements once VAT-registered

Once you are VAT-registered, your invoices must include additional fields on top of the non-VAT requirements:

• Your VAT registration number (in the format GB followed by 9 digits)
• The VAT rate applied to each line item (e.g. 20%, 5%, or 0%)
• The net amount for each VAT rate
• The total VAT amount charged
• The total amount including VAT
• The tax point (time of supply) if different from the invoice date

For supplies under £250 including VAT, a simplified VAT invoice may be used, which has fewer required fields. See the UK VAT invoice requirements guide for full details.

Self Assessment and income records

As a sole trader, you must complete a Self Assessment tax return each year by 31 January (for online submission) covering the tax year to the previous 5 April. Your trading income is reported on the self-employment pages, and you pay Income Tax and Class 4 National Insurance on your profits.

You must keep records of all your income (sales invoices) and allowable expenses for at least five years after the 31 January deadline for the relevant tax year. For example, records for the 2023-24 tax year must be kept until at least 31 January 2030. HMRC can charge a penalty of up to £3,000 for failing to keep adequate records.

Tidybill stores all your invoices permanently and lets you export them at any time, which supports your record-keeping obligations. You can also track expenses against projects to simplify your year-end accounting.

Payment terms and late payment

As a sole trader invoicing other businesses, you have the same rights under the Late Payment of Commercial Debts (Interest) Act 1998 as any other business. You can charge statutory interest at 8% above the Bank of England base rate on overdue invoices, plus a fixed compensation sum of £40, £70, or £100 depending on the invoice value. See the late payment interest guide for details on how to calculate and claim this.

Setting clear payment terms on every invoice and using automated reminder emails reduces the likelihood of late payment. Most freelancers use 14-day or 30-day payment terms.

Sole trader vs limited company

Some freelancers consider incorporating as a limited company, particularly once their income is high enough that the tax and National Insurance savings outweigh the additional administrative burden. The key invoicing difference is that limited companies must display their registered company name, Companies House number, and registered address on all business documents. See the limited company invoicing guide for more on the requirements that apply to incorporated businesses.