It is possible to get Turkish citizenship based on lineage even as an adult. Military service requirement may become an issue for male applicants.
Am I eligible to be a Turkish citizen and how can I get an ID card?
I am 19 years old and I wish to apply for a Turkish ID card. My dad is fully Turkish and was born there, however my mum is English. Could I become a Turkish citizen? And would I be eligible for a Turkish ID card ?
For acquiring Turkish citizenship by paternity, it is sufficient for only one of the parents to be a Turkish citizen at the time of birth; the fact that the other parent is a foreign citizen does not prevent the acquisition of Turkish citizenship. The fact that your father is a Turkish citizen at the date of your birth shows that you have the right to apply for Turkish citizenship and it is sufficient. The application is usually concluded between six months and a year. Registration in the family register of persons who live abroad and have not been notified of their birth despite completing the age of 18 is possible, if it is determined as a result of the examination to be carried out by the Ministry that they have acquired Turkish citizenship due to a Turkish citizen mother or father.