Your country's de minimis value determines if local customs will assess a duty or tax on your shipment. Duties and VAT are calculated as a percentage of the customs value of the goods (item + insurance + shipping). Any duties and taxes on your international shipment will be billed directly to you by the global carrier.
If the package is refused by the receiver or returned due to customs issues it may be subject to a refusal fee. This cost will be deducted from the total cost of the refund.