Invoicing a client in another country.

Most invoices that get rejected abroad are rejected for something small. The work was fine, the amount was agreed, and the document arrives missing one line that the client's accountant needs in order to file it. Then it comes back, three weeks have gone, and the payment terms started counting from the wrong day.

The line is almost always about tax. Either it is not there and should be, or it is there and should not be, or it is absent and the sentence explaining its absence is missing too.

Rules differ by country and by what exactly you sell. Nothing here replaces your accountant. What is portable is the shape of the document.

Charging nothing is not the same as saying nothing

When you sell to a business in another country, the common outcome is that you charge no tax. Your client accounts for it themselves at their end, under their own rate, and claims it back in the same breath. The mechanism has a name, reverse charge, and from your side it looks like an invoice with a zero where the tax usually goes.

Here is where it goes wrong. A zero on its own is ambiguous. There are several reasons an invoice might carry no tax: the seller is not registered, the supply is exempt, the supply is zero rated, or the buyer accounts for it. Those are four different lines on the buyer's return, and their accountant cannot tell which one you meant by looking at a blank.

So the document has to say it. Something like "Reverse charge: VAT to be accounted for by the recipient." One sentence, and the invoice stops being ambiguous.

The four answers a line can give

It helps to stop thinking of tax on an invoice as a number and start thinking of it as an answer to a question. The question is what kind of supply this line is, and there are four usable answers.

A rate. The ordinary case. Twenty percent, nine percent, whatever applies where you are registered. The invoice shows the amount before tax, the tax, and the total.

Zero rated. The supply is taxable, but the rate happens to be zero. Exports of goods often work this way. It counts towards your turnover and it appears on your return.

Exempt. The supply is outside the tax entirely. Certain financial, medical and educational services. It is not zero rated, and mixing the two up will show up when someone reconciles your return.

Reverse charge. You charge nothing and the buyer accounts for it. This is the one that covers most cross border business to business services.

The last three all produce the same zero in the tax column, which is exactly why the document has to name which one it is.

What the client's accountant is looking for

Put yourself at the other end. Someone in another country has your invoice and needs to file it. They are checking for a short list.

Both tax numbers, theirs and yours. The words that make it a tax invoice rather than a request for money. A date, an invoice number that is unique in your books, and a description specific enough to establish what was actually supplied. Then the amount before tax, the tax, and the total, with the rate visible rather than implied.

And, when there is no tax, the sentence saying why.

If your invoice is a PDF you assembled by hand, this is the checklist to run before sending. If it comes out of a tool, this is what to check the tool actually prints.

Selling to a person, not a business

The reverse charge case depends on your client being a business. Sell the same service to a private individual abroad and the answer changes, sometimes to your own rate, sometimes to theirs, and for digital services to consumers there are separate rules with their own thresholds and registrations.

The practical version: get the client's tax number and keep it on file. Having it is what makes them a business for this purpose. Not having it usually means you are in the consumer case, which is the one worth asking your accountant about before the first invoice rather than after the tenth.

The number your own country may want

Separately from any of this, a handful of countries now issue a number per document that has to appear on the invoice. Israel allocates one in real time and the buyer cannot reclaim without it. India issues an IRN, Mexico a UUID. These are not the same thing as your tax registration number, which stays the same all year: they are per invoice, and you get them before the document goes out.

If you are registered somewhere that works this way, that number is part of the invoice, and an otherwise perfect document without it is not usable by your client.

Doing it without thinking about it

Everything above is a checklist, and checklists get skipped on a Friday afternoon. The version that survives contact with a real week is a document that carries the right lines because of how it was made, not because you remembered.

In Orla, tax on invoices lives behind one switch. Each line takes a rate from your own list, or one of the three kinds that carry none, and picking reverse charge makes the invoice print the sentence itself. The client sees the same breakdown on the public page and in the PDF. Where your country issues a number per document, the form asks for it under the right name.

Then, at the end of the quarter, the tax you charged less the tax you paid is already worked out, with the rows behind it ready to hand to whoever files it.