Since April 18, 2020, Turkey has introduced additional customs duties for a larger number of goods tariff numbers.
It levies additional duties on imports from the EU and EFTA if these goods do not originate in the EU or EFTA.
These additional duties are a range of 2% e.g. for various milk products up to 140% for fresh beef.
This could be the reason why importers need certificates of origin for documents from the EU and EFTA.
It is generally advisable to contact the Turkish importer for all goods consignments and to clarify any special features in advance. Other points of contact are the Turkish customs and the German-Turkish Chamber of Commerce abroad (AHK) in Istanbul.
You can find more information at the following link: https://www.trade.gov.tr/