In the UK, the most authoritative source for invoice requirements is HM Revenue & Customs (HMRC). If you are VAT-registered, your VAT invoice must include at least the following:
- A unique invoice number (sequential and used only once).
- Your business name (or trading name) and address.
- Your VAT registration number (GB… or XI… for certain Northern Ireland cases).
- The customer’s name and address.
- The invoice date and, if different, the tax point (time of supply).
- A clear description of the goods or services supplied.
- Quantity and unit price (where relevant).
- The VAT rate(s) applied to each line (e.g., 20%, 5% or 0%) and which items are zero-rated or exempt.
- The total amount payable excluding VAT (net), the total VAT amount, and the total including VAT (gross).
Simplified VAT invoices (for totals of £ 250 or less) may show fewer details, but must still include your name and address, VAT number, the date, a description, the VAT rate(s) and the total gross amount.
Modified VAT invoices may apply in specific retail contexts. If a reverse charge applies (e.g., domestic reverse charge for building and construction), include the wording “Reverse charge: customer to account for VAT to HMRC” and do not show VAT charged.
To whom should you send the invoice?
Send the invoice to the person or team responsible for payment (e.g., Accounts Payable). Before you start working together, confirm:
- the correct billing email or portal,
- the legal entity name to be invoiced, and
- any purchase order (PO) number or reference required.
Building a good relationship with the AP contact is the first step towards effective credit control—and makes resolving any payment queries far quicker.
The invoice number
Your invoice must carry a unique, sequential number. Many businesses use a year-based series (e.g., 2025-0001). Do not skip numbers or reuse a number: gaps raise reconciliation and audit issues.
Invoicing in line with UK law
HMRC’s rules set out what a VAT invoice must contain. If your invoice is missing required elements, customers may reject it or be unable to reclaim VAT—delaying payment.
Key points to remember:
- Use the current date and include the tax point if different.
- Ensure sequential, unique numbering.
- Show your VAT registration number.
- Show the customer’s VAT number only where the rules require it (e.g., certain reverse-charge situations).
- Include full names and addresses for you and the customer.
- Clearly describe quantity, scope and nature of the supply.
- State the date of supply (if different from the invoice date).
- Provide net amount(s) per VAT rate, unit prices (where relevant), and the applicable VAT rate(s).
- Show the VAT amount unless a special rule (e.g., reverse charge) says not to.
- Where a customer self-bills (they issue the invoice), the document should be marked “Self-billing” and follow HMRC’s self-billing rules.
- Where an exemption or special scheme applies (e.g., margin schemes), state this clearly on the invoice.
Correcting an error on an invoice
Do not alter and resend the same invoice number. Instead, issue a VAT credit note referencing the original invoice, then raise a new, correct invoice with a new number.
Government and e-invoicing
Some public-sector buyers require invoices to be submitted electronically (e.g., via a supplier portal or in a specific format such as PEPPOL). Electronic invoices are acceptable in the UK provided the authenticity of origin, integrity of content and legibility are ensured, and all required information is present. Always follow the instructions in the purchase order or contract.
Save time with Payt
Invoices that meet HMRC requirements are paid faster and reduce disputes. Managing outstanding invoices, reminders and queries can be time-consuming—Payt helps you automate the process, maintain clear communications with customers and keep your cash flow healthy.
