Why do some travelers get flagged and detained at Istanbul passport control (name match in database), and what to do?

If you hold two passports, better not to show the second one at passport control back home — border officers can still see it exists in the system anyway. Remaining validity doesn't matter for entry, but a short-validity passport won't work for address registration, so sort that out beforehand.

One traveler, after 10 trouble-free trips, was suddenly stopped at passport control: officers demanded another passport or ID, asked about a visa, and studied her document for a long time. Eventually the officer stamped it, smiled and apologized — resolved, but stressful and time-consuming.

The flagging happens because the border database only stores first name, last name, and birth year. If your name matches a criminal record (even with a different birth year), the system shows a ❌problem, and the officer at the counter doesn't have access to the full database to verify further.

When this happens, you get routed for manual verification: on departure, to the airport visa center; on arrival, to a special police unit. They may also ask if you have a second passport, even though they have no real way to verify the answer.