Money is safest carried in the form of traveller’s cheques; however, these are difficult to change in regional areas. With plenty of ATM’s in major cities more and more people are bringing a combination of cash and credit cards. Look for ATMs displaying either the Maestro, Cirrus, Visa or MasterCard or whatever your card symbol is. ATMs will allow you to access cash (in local currency) from your credit card and possibly from your savings account if it is linked to Maestro or Cirrus or Visa Plus network.
Withdrawn money or the purchase amount will be converted precisely by www.tcmb.gov.tr official rates. If you are bringing cash, then the best currencies are US Dollars, Euro’s or British Pounds. Be aware that most insurance policies will not cover for loss or theft of cash. Credit cards are useful for large purchases but they may not be accepted in small restaurants, mini markets, local transport, taxis. More likely they will only accept cash as payment for goods or services.