“Non-Turkish nationals with a domestic flight connecting to/from an international flight which is booked on the same ticket, do not currently require an HES code.
“Where a domestic flight is booked separately or with a different airline, an HES code is required.
“For international travel, Turkish nationals are required to obtain an HES code, however this does not apply to non-Turkish nationals, including British visitors to Turkey
“For intercity travel, British nationals without a residence card can obtain a HES code by sending their passport details by SMS to 2023 in the following format: HES [space] Nationality (GBR) [space] passport number [space] year of birth [space] surname. Example: HES GBR 123456789 1980 SMITH.