Automated VAT invoicing: what every invoice needs, and what to automate

Most invoicing mistakes are small: a wrong rate, a missing mention, a gap in the numbers. Here is what an EU invoice must contain and which steps are worth automating.

Typing invoices in a spreadsheet or a word processor works for the first ten. Then the mistakes come: last year’s template with the wrong VAT rate, a foreign customer invoiced with domestic VAT, an invoice number used twice, a missing VAT number. Each one means a correction, and in a tax audit, questions. Automating VAT invoicing is less about speed than about never getting these details wrong.

What every invoice must show

In the EU the content of an invoice is set by Article 226 of the VAT Directive (2006/112/EC), taken over by each country. The essentials:

• The date of issue and a sequential number that identifies the invoice uniquely.
• Your name, address and VAT number; the customer’s name and address, and their VAT number when they pay the VAT through the reverse charge.
• What you sold: quantity and description of the goods or services, and the date of supply if it differs from the invoice date.
• For each VAT rate: the net amount, the unit price without VAT and any discount.
• The VAT rate applied and the VAT amount, in the currency of your country even when you invoice in another one.
• When no VAT is charged, the reason: reverse charge, exempt intra-Community supply, export, or an exemption with its legal reference.

The right VAT rate, customer by customer

The rate does not only depend on what you sell. It also depends on who buys and where:

• A customer in your own country: your domestic rate. In Luxembourg the standard rate is 17 %, with reduced rates of 14 %, 8 % and 3 %; in France 20 %, 10 %, 5.5 % and 2.1 %; in Belgium 21 %, 12 % and 6 %; in Spain 21 %, 10 % and 4 %.
• A business in another EU country with a valid VAT number: in most cases 0 % with the reverse-charge mention for services, or an exempt intra-Community supply for goods.
• A private customer in another EU country: usually your own VAT, or the customer’s VAT through the One-Stop Shop (OSS) above €10,000 a year of distance sales and digital services.
• A customer outside the EU: usually 0 %, as an export of goods or a service outside the scope of EU VAT.

This is the step to automate first: when the rate comes from the customer’s country, type and VAT number, nobody has to remember the rules at the moment of invoicing.

Numbering without gaps

Invoice numbers must follow one another without gaps or duplicates. Several series are allowed, for example one per year or per company (F2026-0001, F2026-0002…), as long as each one is continuous. A good practice: an invoice gets its number only when it is final, so a draft you delete never leaves a hole.

Corrections: a credit note, never an edit

Once an invoice is sent, it is not changed. A wrong amount, a returned item or a cancelled job is corrected with a credit note that refers to the original invoice, with its own numbering. The original stays as it was.

Keep invoices, and know what is coming

Invoices must be kept for several years, usually 6 to 10 depending on the country (10 years in Luxembourg), in a form that stays readable and unaltered. E-invoicing is also arriving: in France every company must be able to receive electronic invoices from September 2026 and issue them from 2026 or 2027 depending on its size; in Luxembourg e-invoices are already required for public-sector customers; and the EU plans electronic invoicing and reporting for cross-border B2B sales from 2030. Check with your accountant which dates apply to you.

A checklist to automate

• The VAT rate and legal mention set from the customer’s data, not typed by hand.
• A VAT number checked in VIES before invoicing a foreign business without VAT.
• Numbers given automatically when the invoice is final, per company and year.
• Credit notes instead of edits, linked to the original invoice.
• The PDF e-mailed to the customer in their language, and a copy kept in their history.
• Reminders for unpaid invoices, and every invoice of a period ready for your accountant.

How Tavalle handles it

In Tavalle a delivered order becomes an invoice in one click. The VAT rate and its legal mention come from the issuing company and the customer’s country, type and VAT number, which can be checked in VIES from the customer form. Invoices start as drafts and get the next gap-free number of their series when you finalize them; corrections are credit notes with their own numbering. The PDF is e-mailed in the customer’s language, unpaid invoices get reminders, and the accounting export gives your accountant every invoice of a period in one ZIP with an Excel summary. Tavalle creates PDF invoices: a connection to an e-invoicing platform can be added as implementation work. See invoicing and VAT.

This guide is general information, not tax advice. Rates, mentions and e-invoicing dates differ between countries and change: check your own situation with your accountant.