Hi Patrycja M.,
If you are selling goods from overseas under a value of £135 to consumers then there would be a requirement to register for VAT.
Please see the guidance below:
Changes to VAT treatment of overseas goods sold to customers from 1 January 2021
If the value of the goods is over £135 then you would only need to register for VAT if you are the importer of record for the goods as you would be making a supply of goods within the UK to the final customer.
The transport company should not be using their EORI number if they are not the importer of the goods.
Thank you.