There are no customs duties or anything else to be paid if you are coming from within the European Union, i.e. from one of the following countries:

Austria - Belgium - Bulgaria - Cyprus - Croatia - Denmark (except the Faroe Islands and Greenland) - Estonia - Finland (except the Åland Islands) - France (except the French overseas departments, Saint-Pierre and Miquelon and Maiotta) - Germany - Greece (except Mount Athos) - Ireland - Italy - Latvia - Lithuania - Luxembourg - Malta - Netherlands - Poland - Portugal - United Kingdom (except Channel Islands and Isle of Man) until the end of 2020 - Czech Republic - Romania - Slovakia - Slovenia - Spain (except the Canary Islands) - Sweden - Hungary

If, on the other hand, you are coming from a non-EU country, then you become liable to Customs and Excise Duty as well as Value Added Tax (VAT) payments.