What must a VAT invoice include? HMRC rules mapped to e-invoices

HMRC says a full VAT invoice must show a unique sequential number, the time of supply, the date of issue, your name, address and VAT registration number, your customer's name and address, a description of what you supplied, and for each item the quantity, unit price, VAT rate and amount excluding VAT. It must also show the total excluding VAT, the rate of any cash discount, and the total VAT in sterling. An e-invoice has to carry the same information. Below is where each item goes in a Peppol BIS Billing 3.0 invoice, and what Peppol adds on top.

HMRC's list, word for word

Paragraph 16.3.1 of the VAT guide (VAT Notice 700) says you must show:

• "a sequential number based on one or more series which uniquely identifies the document"
• "the time of the supply (tax point)"
• "the date of issue of the document (where different to the time of supply)"
• "your name, address and VAT registration number"
• "the name and address of the person to whom the goods or services have been supplied"
• "a description sufficient to identify the goods or services supplied"
• "for each description, the quantity of the goods or the extent of the services, the rate of VAT, and the amount payable excluding VAT, this can be expressed in any currency"
• "the gross total amount payable, excluding VAT, this can be expressed in any currency"
• "the rate of any cash discount offered"
• "the total amount of VAT chargeable, this must be expressed in sterling"
• "the unit price"

VAT Notice 700/63 on electronic invoicing is direct about e-invoices: "Electronic invoices must contain the same information as paper invoices."

Where each item goes in a Peppol invoice

HMRC requirement	EN 16931 business term	UBL element
Sequential unique number	BT-1 Invoice number	cbc:ID
Time of supply (tax point)	BT-7 VAT point date, or BT-72 Actual delivery date / BG-14 Invoicing period	cbc:TaxPointDate, cac:Delivery/cbc:ActualDeliveryDate, cac:InvoicePeriod
Date of issue	BT-2 Invoice issue date	cbc:IssueDate
Supplier name	BT-27 Seller name	cac:PartyLegalEntity/cbc:RegistrationName
Supplier address	BG-5 Seller postal address	cac:AccountingSupplierParty/cac:Party/cac:PostalAddress
Supplier VAT number	BT-31 Seller VAT identifier	cac:PartyTaxScheme/cbc:CompanyID (with GB prefix)
Customer name and address	BT-44 Buyer name, BG-8 Buyer postal address	cac:AccountingCustomerParty/...
Description	BT-153 Item name, BT-154 Item description	cac:Item/cbc:Name, cbc:Description
Quantity or extent	BT-129 Invoiced quantity, BT-130 unit	cbc:InvoicedQuantity/@unitCode
Unit price	BT-146 Item net price	cac:Price/cbc:PriceAmount
VAT rate per item	BT-151 category, BT-152 rate	cac:ClassifiedTaxCategory
Amount excluding VAT per item	BT-131 Invoice line net amount	cac:InvoiceLine/cbc:LineExtensionAmount
Total excluding VAT	BT-109	cac:LegalMonetaryTotal/cbc:TaxExclusiveAmount
Cash discount rate	No dedicated field; BT-20 Payment terms (text)	cac:PaymentTerms/cbc:Note
Total VAT in sterling	BT-110, or BT-111 with BT-6 if not invoicing in GBP	cac:TaxTotal/cbc:TaxAmount

Some notes on the trickier rows.

Trading names. HMRC lets you invoice under a trading name, but "you must show the name and address under which you're registered for VAT somewhere on the document". In Peppol, the registered name goes in BT-27 (RegistrationName) and the trading name in BT-28 (cac:PartyName/cbc:Name).

Tax point. BT-7 (cbc:TaxPointDate) is the explicit field. Many invoices use the delivery date or invoicing period instead. You cannot send both BT-7 and the BT-8 date code (rule BR-CO-03). Whether the UK will require BT-7 on every invoice is not yet confirmed.

VAT number format. BR-CO-09 requires the VAT identifier to start with a country prefix: GB123456789, not 123456789.

Cash discount. EN 16931 has no structured cash discount field, so the terms go in free text in payment terms. If you offer prompt payment discounts, HMRC's guide (paragraph 18.2.2) also sets out wording for the invoice when you will not issue a credit note.

What Peppol requires on top of HMRC

A Peppol invoice that meets every HMRC requirement can still be rejected. Peppol BIS Billing 3.0 and EN 16931 add mandatory items HMRC does not ask for, including:

• Electronic addresses for both parties. PEPPOL-EN16931-R010: "Buyer electronic address MUST be provided". R020 says the same for the seller.
• A buyer reference or purchase order reference. PEPPOL-EN16931-R003: "A buyer reference or purchase order reference MUST be provided." See buyer reference (BT-10).
• Specification and process identifiers (BT-24, BT-23) with fixed Peppol values.
• Country codes in both postal addresses (BR-09, BR-11), even for domestic invoices.
• A VAT breakdown per VAT category and rate (BR-CO-18), and totals that add up exactly (BR-CO-10 to BR-CO-16).

Some HMRC requirements are only partly enforced. Peppol requires an item net price on every line (BR-26), but no validation rule checks that your numbering is sequential, that the description is "sufficient", or that the tax point is right. Those stay your responsibility.

Special cases

Zero-rated and exempt items on the same invoice. HMRC says these must "show clearly that there's no VAT payable" with "a separate total for their values". Peppol's separate VAT breakdown per code (Z, E) does this. See UK VAT category codes in Peppol.

Reverse charge. Extra wording is required. See reverse charge construction e-invoices.

Foreign currency. Amounts can be in any currency, but VAT Notice 700/63 says "you must express the total amount of VAT in sterling where there is a positive rate of VAT due in the UK". See multi-currency e-invoices.

Simplified invoices (£250 or less). HMRC allows a shorter invoice for supplies of £250 or less including VAT. Whether simplified invoices fall within the 2029 mandate is not yet confirmed. See retail receipts and simplified invoices.

Self-billing. HMRC requires self-billed invoices to include the reference "self billing". Peppol has invoice type code 389 (self-billed invoice). See self-billing and e-invoicing.

Timing. You must normally issue a VAT invoice within 30 days of the tax point. Nothing announced so far changes that.

What the 2029 mandate may change

From April 2029, VAT invoices for B2B and B2G supplies must be e-invoices. Today's HMRC content rules are the starting point, but the UK e-invoice specification has not been published. The government has said it will consider "adopting an existing standard or designing a UK-specific standard". A UK specification could make fields mandatory that are optional now, such as tax point date, buyer VAT number or unit price. None of that is confirmed yet. The roadmap is due at Budget 2026 on 28 October 2026. Check the mandate overview.

What to do now

• Run a sample of your current invoices against HMRC's list above.
• Make sure your system stores structured data for each item, not just a PDF: quantity, unit price, VAT rate and net amount per line.
• Clean up customer master data: legal names, full postal addresses with country codes, and GB-prefixed VAT numbers. See master data clean-up.
• See a complete UK Peppol invoice XML example.