The insurance has to cover the whole permit

The mismatch that gets files refused

People buy a twelve-month policy, then ask for a two-year permit. The office looks at the two dates and the file stops there. The fix is to decide the permit length first and buy insurance to match, which is the opposite of the order most people do it in.

What the office accepts

Turkish insurers sell policies written for this purpose, and they know the format. Foreign policies are sometimes accepted and sometimes not, which makes them a gamble on a document you can buy cheaply and locally instead.

Applicants aged 65 and over are treated differently, and that is worth asking about rather than assuming either way.

Cost, roughly

Turkish sources put a basic policy somewhere in the low thousands of lira a year, varying with age and cover. Next to the permit fee it is a small line. Next to a refused application it is smaller still.