There are new local regulations for A2P (Application to Person) SMS delivery to persons in Turkey, we are now required to start registering all source addresses (aka sender ID) to be used.
If you do not own the brand or trademark being used as the source address, you will need supply a letter from the owner of the brand or trademark, giving you express permission to use the brand or tradmark as the source address with us.
Using our direct tier 1 connections to Turkey this will take effect from April 2016. If you have any questions or to register source addresses please contact us.