Turkey has a VAT known as the katma değer vergisi (KDV). This means that 18% tax is added to the price of most goods and services. If non-residents buy an expensive item from a shop that participates in the national Global Refund: Tax Free Shopping scheme and then take the item out of the country within three months, they are entitled to a refund of the KDV. Some shops display a “Tax Free Shopping” sign in their window, signalling that they are participants in the scheme.
The shopkeeper will issue you with a refund receipt which can be brought to the airport and stamped to confirm you are leaving the country, whereupon the refund can be collected from a booth in the departure longue in the form of cash (Turkish lira) or a credit to your chosen credit card account.