Tariffs are not included in the cost of goods.
Customers need to pay their own customs duties, and the amount is determined by the customs.
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Starting from January 1, 2021, products shipped to the UK below 135￡ will be collected and paid by eBay for VAT. For products higher than 135￡, buyers need to pay tariffs themselves.

Starting from July 1, 2021, VAT will be collected and paid by eBay for products shipped to the EU for less than 150€. For products above 150€, buyers need to pay tariffs themselves.