As of April 17, 2013, electronic visa (e-Visa) replaces “sticker visa” which was issued at the border crossings. Applicants just need to log on to www.evisa.gov.tr , provide the requested information, (after the application is approved) make online payment and download their e-Visa.
Please note that e-visa is only valid when the purpose of travel is tourism or commerce. Other purposes, such as work and study, require regular visa given by Embassies or Consulates.
Passports should be valid at least six months longer than the expiry date of the requested visa.
The term "official passports" covers diplomatic, service, special and official passports.
Visa regime for truck drivers of a country may differ from the overall visa regime effective for citizens of that particular country. For further information, please contact the nearest Turkish mission.
Foreigners who will shoot a documentary film conduct a research or an archeological excavation should get a special permission from the Turkish authorities in advance.
You can see more information here