ENTRY REQUIREMENTS

A visa is required for British nationals to enter Turkey.  For further information on entry requirements, you should check with: Turkish representation in UK

In addition to the Embassy in Ankara there are Consulates in Istanbul, Izmir and Antalya and honorary Consulates in Bodrum, Marmaris and Bursa. Full contact details are on the Embassy website.
British Embassy in Turkey

Visa information for all other Countries: Turkish ministry of foreign affairs
Inform you und make your visa  application in person and one month before you proceed to Turkey to avoid any inconvenience.