The moment you send an invoice across the EU, you’re not only “doing the paperwork” you’re protecting cash flow. If the invoice can’t be processed, the payment stalls. If the VAT treatment is wrong, the risk lands on you. And the smallest businesses feel that fastest: one delayed invoice can bend a whole month.

Start with the part most people skip because it feels obvious: check whether your EU customer has a valid VAT number. In plain terms, this is what decides whether you can invoice at 0% VAT for an intra-Community supply, or whether you may end up owing Dutch VAT later. The Dutch tax office is very direct about it: both VAT IDs must be on the invoice and you must check the customer’s VAT ID. And note the Dutch nuance: the number you use for cross-border checks is the btw-id (VAT ID), not your “VAT tax number” (omzetbelastingnummer). KVK even warns that checking the wrong Dutch number can produce the “invalid” message and send people down the wrong path. The VIES tool is the EU’s official way to verify VAT IDs. 

What happens if you don’t check, and the VAT ID turns out not to be valid at the moment of supply? Then the neat “0%” can become an expensive misunderstanding: the tax authority may treat it as if the conditions were not met, and you’re the one who has to fix it, often with a corrected invoice, extra VAT due, and a customer who suddenly disputes the total because they never budgeted for your VAT. This is exactly the kind of problem that looks small in the spreadsheet and feels big in the bank account. It’s also why your invoice wording matters: for intra-Community supplies the Dutch tax office expects an indication on the invoice that it’s such a supply, with references you can use in any language. (And when reverse charge applies in general, the Dutch tax office is equally clear: don’t put VAT on the invoice and state that VAT is reverse-charged. 

Now the second shift that’s sneaking up on micro-businesses: e-invoicing. An e-invoice is not “a PDF by email”. It’s a structured invoice (often XML/UBL) that systems can read and route, sometimes through a government platform or a network such as Peppol. Countries are moving at different speeds, but the direction is one way. Italy has required e-invoicing for VAT-registered businesses via its SDI system since 1 January 2019.  Belgium has confirmed mandatory structured e-invoicing for B2B from 1 January 2026. France is working with a phased start from 1 September 2026, with smaller businesses following later.  Poland has signed in a mandatory national platform (KSeF) effective from 1 February 2026. And Germany already requires businesses to be able to receive EN-compliant e-invoices from 1 January 2025, with issuing requirements phased later. 

In practice, this shows up in the most irritating way: you send a “perfectly normal” invoice, and the customer replies, “We can’t accept this, please send it via Peppol / SDI / our platform.” Nothing is technically wrong with your work; the invoice simply can’t enter their approval process, so it can’t reach their payment run. If you want one simple habit that saves disproportionate stress, make this part of onboarding: when you agree the contract, ask how they need to receive invoices, and whether they require a specific format or network. Then make sure your accounting software can produce a structured e-invoice when needed (or that you have a provider/portal ready), and write into your payment terms what counts as “received” when a platform is involved.

The calm conclusion is this: you don’t need a tax department to stay safe, you need a tighter routine. Check the VAT ID in VIES at the moment it matters and keep proof of the check. Put the right VAT IDs and the right wording on the invoice. And treat e-invoicing readiness as part of commercial hygiene, like confirming a delivery address. Small adjustments, done early, keep invoices boring, and boring invoices get paid.