What must an invoice include? EU and UK VAT invoice checklist

A valid VAT invoice must show who sold what to whom, when, for how much, and how much VAT is due. In the EU, the list of mandatory details is set by Article 226 of the VAT Directive (2006/112/EC), which every member state applies through its own VAT law. In the UK, HMRC sets out a very similar list in VAT Notice 700 and VAT Notice 700/21. Use the checklist below as your baseline, then check what your own country adds, such as e-invoicing.

The mandatory details on an EU VAT invoice (Article 226)

Two more EU rules are easy to miss:

• Currency (Article 230): you may invoice in any currency, but the VAT amount must also be shown in the national currency of the country where the VAT is due.
• Deadline for cross-border invoices (Article 222): for intra-EU supplies of goods, and for services where your customer pays the VAT under the reverse charge, the invoice must be issued by the 15th day of the month after the supply. Each country sets its own deadline for domestic sales.

If a single detail is missing, your customer may not be able to deduct the VAT, and many companies will simply not pay an invoice their accountant rejects.

UK VAT invoices: what HMRC requires

A full UK VAT invoice must show:

• a unique invoice number that follows on from the previous one (you may use more than one series)
• the time of supply (tax point) and the issue date, if different
• your business name, address and VAT registration number
• your customer's name and address
• a description of the goods or services, with the quantity or extent
• for each item: the unit price, the VAT rate and the amount excluding VAT
• the total excluding VAT, the rate of any cash discount, and the total VAT, shown in sterling even if you invoice in another currency

HMRC accepts three kinds of VAT invoice:

You should normally issue a VAT invoice within 30 days of the tax point. Exempt supplies must not appear on a simplified invoice.

Details that are optional but get you paid

The law does not always require these, but clients pay faster when they are on the invoice:

• A clear due date (“Due 15 November 2026”), not only “30 days”
• Bank details: bank name, account number or IBAN, and SWIFT/BIC for foreign clients
• An online payment link, so the client can pay by card in a minute
• The client's purchase order number, which many companies need before approving payment
• A contact person for questions about the invoice
• Late-payment terms, for example statutory interest after the due date

Our guide on how to get paid faster covers the rest.

How invoice numbering works

Invoice numbers must be unique and follow a continuous sequence, so a tax inspector can see that no invoice was removed. Both the EU Directive and HMRC allow more than one series:

• You may run separate series, for example one per year or per branch (2026-0417), as long as each series has no gaps.
• A cancelled invoice keeps its number. You correct it, you do not delete it.
• Proformas and quotes are not invoices and should use their own numbering.

How to correct an invoice: credit notes

Once an invoice is sent, it is part of your records. Under Article 219 of the EU Directive, a document that amends an invoice and refers to it specifically and unambiguously is treated as an invoice itself. In practice that is a credit note (some countries call it a corrective invoice). If something is wrong:

1. 1Issue a credit note that references the original invoice number and date and cancels it fully or partly.
2. 2Issue a new invoice with the correct details, if needed.
3. 3Send both to the client, so their books match yours.

In the UK, HMRC expects a credit note to show its own number and date, your name, address and VAT number, your customer's name and address, a description of what is credited with the quantity and amount, the total credited excluding VAT, the rate and amount of VAT credited, and the number and date of the original invoice.

Simplified invoices for small amounts

The EU Directive requires every member state to accept a simplified invoice for amounts of up to €100 (Article 220a), and lets countries go up to €400 (Article 238). Germany, for example, accepts small-amount invoices up to €250, and the UK allows simplified invoices up to £250. A simplified invoice needs at least the date, the seller's identity, the type of goods or services and the VAT amount (or what is needed to calculate it). It cannot be used for intra-EU supplies of goods or distance sales to consumers in other EU countries. Receipts from a cash register follow separate national rules.

E-invoicing mandates: what changes and when

An e-invoice is a structured file, usually XML following the European standard EN 16931, that software can read without anyone retyping it. A PDF sent by email does not count. Many countries are making e-invoices compulsory between businesses:

The dates and VAT rates behind these rules are in our VAT guide.

How long to keep invoices

The EU Directive lets each country set its own storage period, and e-invoices must stay readable and unaltered for the whole of it. Some examples:

• United Kingdom: at least 6 years for VAT records.
• Ireland: 6 years, or until an open matter with Revenue is finalised.
• Netherlands: 7 years, and 10 years for records on real estate and for the OSS.

Keeping invoices in a cloud system makes this automatic, as long as you can still export them if you change provider.

7 invoice mistakes that delay payment

1. 1Sending the invoice weeks after the work is done.
2. 2A wrong or missing VAT number for the client, or one you never checked in VIES.
3. 3A vague description such as “Services” with no period or reference.
4. 4No due date, or a due date the client never agreed to.
5. 5Sending it to a general email address instead of the person who approves payments.
6. 6Bank details missing or out of date.
7. 7Totals that do not add up because VAT was rounded per line on one side and on the total on the other.

Checklist before you hit send

• Number and date are correct, and the number follows on from the last one
• Client name, address and VAT number match their registration
• Each line has a clear description, quantity, unit price and VAT rate
• Totals per VAT rate add up, and the VAT total is in your national currency
• If no VAT is charged, the invoice says why (exemption or “Reverse charge”)
• Due date, bank details and payment link are on the invoice
• It goes to the person who approves payments

How Clientlly handles this

Clientlly fills in the mandatory details for you: sequential numbering per series, your country's VAT rates on every invoice, credit notes linked to the original invoice, the PDF in your client's language, a card payment link, and automatic reminders 3, 14 and 30 days after the due date. Fiscal printers are supported where a country requires them. See the invoicing module.