A VAT number (or VAT payer number) is a unique identification number confirming that a company is registered with tax authorities as a Value Added Tax (VAT) payer in the European Union. In Poland, the VAT number corresponds to the tax identification number NIP (Numer Identyfikacji Podatkowej), which is assigned to a company at the time of its registration. For conducting foreign economic activities, buying and selling, or providing services outside Poland in countries where the tax system includes Value Added Tax, a company is obliged to be registered as a VAT and VAT-UE payer.

All international transactions between Polish and foreign VAT-registered counterparties are subject to a zero VAT rate. However, if the customer for your services or goods, located outside Poland, pays your invoice, and your company is not registered as a VAT payer, they will be obliged to pay Value Added Tax on the transaction amount in their country.