Provision of services
The end of the transition period on December 31 2020 will most probably change the way some services are provided by Polish taxpayers to British non-taxpayers. Those services are listed in Article 28I of the Polish Act on VAT and cover such services as: licensing, advertising, advisory services, legal services, financial services. At this moment such services are taxed in Poland with Polish VAT rate. Starting from January 1, 2021 provision of such services for the persons residing in the UK shall not be taxed under Polish VAT regime.
Until transition period ends Polish taxpayer providing transport service to a non-taxpayer is obliged to apply VAT according to the Polish tax rules. When the transition period ends such transport to the UK and from the UK shall be treated as international transport as in Article 83 Paragraph 3 of the Polish Act on VAT. That means that transport services from Poland to the non-taxpayer in the UK should be taxed with 0% VAT rate for the transport that happens on the territory of Poland (with the proper documentation) and when the goods cross territory of Poland such transport will be outside of Polish VAT regime and will not be taxed in Poland.
Transport on the territory of Poland
According to the Article 28f of the Polish Act on VAT when the whole transport of goods happens on territory of Poland and is provided to a taxpayer from a third country (UK when the transition period ends) then it shall be taxed in Poland. The British taxpayer will be able to retrieve VAT paid in Poland based on the regulations from EU 13th VAT Directive.
Check our service VAT compliance in EU https://europe-tax.com/services/vat-compliance-europe/