From our work at Biuro Precyzja
Clients most often assume that an invoice showing the customer's VAT number is all they need to sell abroad.
For intra-Community supplies of goods (WDT), they often overlook arranging VAT-UE registration in Poland, checking the customer's VAT number in VIES, and collecting evidence that the goods left Poland and were delivered to the buyer in another EU country — without that evidence, applying the 0% VAT rate may be at risk.
That is why, for sales of goods, we collect the order or contract, including the delivery terms, and transport documents; for WDT, we also keep confirmation that the customer's VAT number was checked in VIES.
For exports outside the EU, we collect proof of export, such as a CC599C message (formerly IE-599) from AES/ECS2 PLUS confirming that the goods have left the EU.
We also establish the invoice date, the date of delivery or service performance, and the payment date, which are needed to account for the transaction correctly and convert amounts in foreign currencies, including applying the appropriate National Bank of Poland (NBP) exchange rate.