Understanding VAT and Tax IDs

Aisha, a freelance illustrator in London, landed a dream client in Germany. She sent the invoice, forgot her own VAT number, and omitted the client's. The German accountant rejected it. Aisha had to reissue, and the payment slipped an extra two weeks. The art was perfect. The tax line was the problem.

Tax rules vary by country, but the basics are similar everywhere: say who charges tax, at what rate, and to whom. Get those three right and cross-border billing stops being scary. Here's the practical version.

Show your own tax or VAT ID

If you're registered for tax, your ID belongs on every invoice you send. Clients need it for their own books, and in many places a missing ID makes the invoice invalid for their records.

In the EU and UK, that means your VAT number, formatted with the country code (GB, DE, FR, and so on). Put it near your business name, top of the document, where a finance team looks first. A freelance invoice without it is the fastest way to get bounced back.

Not sure which fields your invoice needs overall? Our guide on What to Include on Every Invoice lists them all.

The EU reverse-charge rule

Here's the one cross-border rule freelancers mix up most. When you sell a service from one EU country to a business in another, you usually don't charge VAT on the invoice. Instead, the reverse-charge mechanism applies: the VAT shifts to the customer's side.

For that to work, two things must be on the invoice:

• Your VAT number
• The client's VAT number

And you should state clearly that reverse charge applies, something like "Reverse charge: VAT liable by the customer." Without the customer's VAT number, the reverse-charge treatment can fall apart, and you could end up on the hook for tax you didn't collect.

Apply the rate for the place of supply

The rate you use depends on where the supply takes place, not where you happen to sit. For most B2B services, that's the customer's location. For physical goods or certain digital products, the rules differ, so check the specific threshold for the client's country.

A simple habit: when a new country is involved, spend five minutes on the local tax authority's site before you invoice. If you're below a registration threshold, you may not need to charge VAT at all. When in doubt, ask an accountant. The cost of one call beats the cost of a wrong tax bill.

Our breakdown of invoice vs receipt vs bill covers why a proper VAT invoice (not just a receipt) is what other businesses need to reclaim tax.

Keep records that satisfy both sides

Tax authorities on both ends of a cross-border job may want to see your invoices. Keep them in a format that's readable and complete. A clean PDF with both VAT numbers and the rate shown is far easier to defend than a one-line email if questions come up later.

This matters most when you bill international clients, where two sets of rules apply at once. Build the habit now and audits stay boring, which is exactly what you want.

The short version

• Put your own tax or VAT ID on every invoice; clients need it for their books.
• In the EU, include the customer's VAT number for cross-border reverse-charge invoices.
• Apply the rate for the place of supply, and check the local threshold when in doubt.

Master those three and VAT stops being the thing that delays your payment. Show the IDs, state the rule, charge the right rate, and your invoice clears finance on the first pass.

This article is for general informational purposes only and is not legal or tax advice.