Thank you for your input, Mark! The thing is that all HS codes are 6 digit ones for e-comm in the EU and the declaration was cleared electronically and the proof is the status ZC299H7. However when we physically arrive at the customs point, the customs officials cannot see our declaration in their system. We are not a customs broker, maybe customs brokers in Poland have a different customs program to submit declarations? Is it possible to advise the program which customs brokers use in the EU?