Istanbul Car Hire: Istanbul airport is home to a number of car hire companies, some are large international companies and some local agents operate from here. We recommend booking your car hire in advance, it's one less thing to have to do when arriving in Istanbul and it saves the disappointment of not being able to get the car you require for your holiday.

In order to help things go smoothly you'll need to remember a few things that are expected by the car hire companies.
It sounds obvious but
bring your driving licence! Both parts are required if you hold a UK driving licence.
A second form of ID is required, your passport will be sufficient for this.
The designated driver will need to present his or her credit card, this is used for authorisation against any potential claims for damage that result form your hiring of the vehicle.
If you book online with one of the large car hire companies they should tell you what is required in order to hire a car when you arrive at the car hire desks at Istanbul airport. If you have any questions you should contact them and resolve the issues before travelling.