When transporting goods across international borders, shipments are subject to duties and taxes as determined by customs in the destination country.
You may be charged customs duties and taxes for something purchased online .
When goods are not shipped domestically (within your country) or within a single customs union, such as the European Union, you are liable to pay any inbound duties and taxes which your local customs authority deems appropriate.
If you choose a courier service (such as DHL), depending on the local customs, customs duties may be generated, and you need to pay the tariff yourself.
What is payable, if anything, depends on where the goods are sent from, the type of goods, their transactional value and the weight of the package.