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Business6 min readUpdated: 2026-11-02

UK Invoice Requirements: Legal Checklist for Sole Traders & Limited Companies

Sending incomplete or incorrect commercial invoices can lead to delayed client payments, disputes, and non-compliance penalties under the UK Companies Act. Here is the complete legal checklist for invoicing clients properly.

Authored by: UtilityFinch Editorial Team•Business Compliance

📌 Key Takeaways

  • ✓Invoices must include a unique sequential invoice number and the date of issue.
  • ✓Sole traders must display their own personal name plus any trading name and an address where legal documents can be served.
  • ✓Limited companies must show their registered company name, registered office address, and Companies House registration number.
  • ✓VAT-registered businesses must include their 9-digit VAT number, itemized tax rates, and total VAT charged.
  • ✓Payment terms and statutory 30-day payment defaults under the Late Payment of Commercial Debts Act should be stated clearly.

1. Sole Trader vs Limited Company Requirements

UK law makes distinct demands depending on whether you trade as a self-employed sole trader or an incorporated limited company (Ltd):

For Sole Traders: You must state your full legal name, your trading name (if different, e.g. "Jane Doe trading as JD Design"), and a business address where official documents can be delivered.

For Limited Companies: You must show the exact registered name as listed at Companies House, your registered office address, and your 8-digit Company Registration Number (CRN). If you choose to list directors, you must list all directors.

2. Mandatory Invoice Content Checklist

Under UK commercial regulations and HMRC guidelines, every valid invoice must contain:

FieldRequirementDetails
Invoice NumberMandatoryUnique sequential number with no duplicates (e.g. INV-2026-001)
DatesMandatoryDate of issue and the date the goods/services were supplied (tax point)
Client InformationMandatoryCustomer business name and billing address
Description of SupplyMandatoryClear itemized description of services or products supplied
Unit Pricing & QuantitiesMandatoryQuantity, hourly rate or unit price, and subtotal per line
Total Amount DueMandatoryNet amount, applicable taxes/discounts, and gross total payable
Payment InstructionsEssentialSort code, account number, IBAN/BIC, and payment due date

3. Additional Rules for VAT-Registered Businesses

If you are VAT registered, your document is legally a "VAT Invoice". It must include your official 9-digit GB VAT registration number.

Furthermore, each line item must specify the applicable VAT rate (20%, 5%, 0%, or exempt), and the invoice summary must display the total VAT amount charged in sterling (£).

Our free online Invoice Generator produces professional, vector-sharp PDF invoices in your local browser, pre-configured with all UK statutory fields.

💡 Prompt Payment Tip

Under the Late Payment of Commercial Debts (Interest) Act 1998, you have a statutory right to charge interest (8% plus Bank of England base rate) plus fixed compensation on overdue commercial invoices.

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