Poland Ecommerce Regulations
PKWiU codes - if you sell products/services with tax rate different than usual 22% you should give PKWiU product code on the invoice. This is used for example in case of books. Codes look like 26.30.22 (phones for cellular or other wireless networks).\
i’m not sure if this is required but usually on an invoice you give NIP (tax number) and REGON (statistical classification number) of buyer (if it is a company).\
NIP is required if the customer is a company. REGON is not required at all.
Prices rounded to 0.1 PLN (or zł) = 10 gr\
All prices shown including VAT, on invoice good to state VAT rate for given product. Not sure how it works for customers outside Poland but for local both companies and individuals the invoices looks the same and contain prices with VAT. \