What is a VAT number, and how do you invoice an EU client?

You are billing a client in Germany, buying software from a supplier in Ireland, or a new partner has just asked for “your VAT number”. The VAT number is the backbone of every business to business transaction inside the European Union, and it decides whether you charge tax or not. Here, without the jargon, is what it is, how to get one, how to check it, and above all how to invoice an EU client correctly in 2026, with the mandatory wording and a worked example.

What is a VAT number, exactly?

A VAT number (VAT identification number, or VAT registration number) is an individual tax identifier assigned to every business registered for Value Added Tax. Think of it as a fiscal passport: it identifies you to tax authorities and to your trading partners whenever goods or services cross a border between two member states.

Its job is twofold. For you as a seller, it is what allows you to invoice a business customer in another EU country without charging VAT. For the tax authorities, it guarantees the VAT will still be collected somewhere, namely in the buyer’s country. That mechanism, the reverse charge, is what keeps cross-border trade tax-neutral instead of taxing the same sale twice.

What does a VAT number look like?

The format changes from one country to the next, but the logic is identical everywhere: a two-letter country code followed by a series of digits, and sometimes letters. Here are the common patterns you will run into:

Indicative reference patterns, current at Q3 2026. The number and type of characters differ by member state, which is exactly why you should always run the official check rather than trust how a number looks.

How do you get a VAT number?

It depends on whether you are already registered for VAT. Two situations arise:

Thresholds vary widely. In the UK, you must register once your taxable turnover passes GBP 90,000 over any rolling 12-month period, a level held for the 2025/26 and 2026/27 tax years (source: GOV.UK, Q3 2026). Most EU countries have far lower thresholds, and non-resident sellers holding stock in a country often have to register from the very first sale. Always confirm the current rule for the country you are trading into.

How do you verify a VAT number on VIES?

This is the step too many businesses skip, and it is decisive. Before you zero-rate a sale to a customer in another EU country, you must verify that their VAT number is valid. The official tool is VIES (VAT Information Exchange System), a free service run by the European Commission that queries each country’s national database in real time.

You enter the customer’s number and VIES confirms, instantly, whether it is active and which trader it belongs to. If the number is invalid or not found, you are not entitled to zero-rate the sale: you must charge VAT at your own country’s standard rate instead. Keep proof of every check (date, screenshot or consultation reference), because in an audit the burden is on you to show the number was valid when you issued the invoice.

How do you invoice an EU B2B client?

Once the customer’s number checks out, the general rule for a sale between businesses in two member states is the reverse charge. The principle: the seller issues an invoice with no VAT, and the buyer accounts for the VAT in their own country while deducting it at the same time. For a VAT-registered buyer, the operation is cash-neutral and no double taxation occurs.

The mechanics differ slightly for goods and services:

• Supply of goods (you ship a product to another member state): the sale is exempt on the seller’s side, provided you hold a valid VIES number and proof of transport. The buyer makes a taxed intra-community acquisition at home.
• Supply of services (consulting, development, design, marketing and so on): under the general place of supply rule (Article 44), taxation sits in the customer’s country. You invoice with no VAT and the client reverse charges it.

On the buying side the logic is symmetrical: when you purchase goods or services from an EU supplier, you self-assess the VAT on your own return, collecting and deducting it on the same return so the effect is neutral if you have full recovery.

What wording is mandatory on an EU invoice?

An EU cross-border invoice carries all the usual mandatory fields of any invoice, plus two specifics: both VAT numbers (yours and the client’s), and a statement that justifies the absence of VAT. Article 226 of the VAT Directive lists the required fields.

Sources: Directive 2006/112/EC (articles 44, 138, 196 and 226), European Commission taxation and customs guidance, current at Q3 2026. The exact article reference depends on the precise nature of the supply, so confirm your case with an accountant.

What if the client is a consumer (B2C)?

Everything above concerns business to business trade. The moment your customer is a private individual in another EU country (B2C), the rules change, because they have no VAT number to reverse charge.

For distance sales of goods and certain digital services to EU consumers, a single EUR 10,000 annual threshold, across all EU countries combined, applies. Below it, you charge your own country’s VAT. Above it, you must charge the VAT rate of the customer’s country and can report it through the One Stop Shop (OSS), which spares you from registering in every country.

What changed for UK VAT after Brexit?

Since the UK left the EU VAT area, a few things differ. UK GB VAT numbers are no longer in VIES, so an EU customer cannot check them there (Northern Ireland “XI” numbers, used for goods, still can be). A UK business selling services to an EU company still sees the reverse charge apply in the buyer’s country, and a UK importer or exporter now deals with customs and import VAT that did not exist for intra-EU trade.

Domestically, the UK standard VAT rate is 20%, with a 5% reduced rate and a 0% zero rate. If you need the mechanics of the maths, see our guides on adding VAT to a price and removing VAT from a gross figure.

A worked EU invoice example

Take a common case. A UK agency sells a development project for GBP 2,000 to a company in Belgium. The client provides the number BE0123456789, which the agency checks on VIES: valid.

The invoice shows the agency’s own VAT number and the client’s Belgian number, a net total with a 0.00 VAT line, and the wording “Reverse charge, Article 196 Directive 2006/112/EC”. On receipt, the Belgian client self-assesses and deducts the Belgian VAT on its return. No VAT was charged, and the transaction is perfectly neutral.

Should you handle EU VAT by hand?

For a one-off invoice, a well filled template can do the job. But as soon as cross-border trade multiplies, manual handling stacks up risk: forgetting to check the number on VIES, missing the reverse charge wording, charging VAT by mistake, or never filing a recapitulative statement. Each slip weakens your bookkeeping and exposes you in an audit.

A serious invoicing tool validates the client’s VAT number, applies the correct treatment automatically (zero-rated with the right wording for goods or services), separates B2B from B2C, and prepares your reporting. The stakes rise further with e-invoicing, which several countries are phasing in through 2026 and 2027. A tool wired into a compliant platform handles cross-border rules with no re-keying.