How many digits is a Turkish postal code?

A Turkish posta kodu is exactly 5 digits, for example 34000 for Istanbul. The first two digits are the province plate code from 01 to 81 and the remaining three narrow it to a delivery zone. Anything that is not 5 digits is not valid.

What do the first two digits mean?

The first two digits are the province (il) plate code, the same numbering used on vehicle licence plates. 34 is Istanbul, 06 is Ankara, 35 is Izmir. This validator maps that two-digit prefix to the province name.

Why are 00 and 82 to 99 invalid prefixes?

Turkey has 81 provinces numbered 01 to 81. A leading prefix of 00 or anything above 81 does not correspond to a province, so the validator flags it. The 5-digit format may look right but the province cannot be resolved.

Does a valid format mean the address exists?

No. The tool confirms the 5-digit format and a real province prefix, but it does not hold the full PTT delivery-zone database, so a structurally valid code may not be an active zone. Treat the province mapping as a strong hint, not a delivery guarantee.

Is my data sent anywhere?

No. Validation and the province lookup run entirely in your browser with a built-in table. Nothing is transmitted, so the tool is safe to embed in checkout flows that handle customer addresses.

Turkey Postal Code Validator

A Turkish posta kodu is a 5-digit code where the first two digits are the province (il) plate code, ranging from 01 to 81. That makes province lookup a simple prefix match. This tool validates the format and maps the prefix to a province, all in your browser.

How it works

Validation has two parts:

Format: after removing spaces, the value must be exactly 5 digits 0–9.
Province mapping: the first two digits are read as a province plate code. Turkey has 81 provinces numbered 01–81; the tool looks the prefix up in a built-in table. For example 34 → Istanbul, 06 → Ankara, 35 → Izmir.

A prefix of 00 or anything above 81 is not a province and is reported as invalid even though the 5-digit shape is correct.

Example

34000  →  valid, Istanbul
06000   →  valid, Ankara
35000   →  valid, Izmir
99000   →  invalid province prefix (no province 99)
1234     →  invalid (only 4 digits)

Notes

The two-digit prefix resolves the province reliably because it mirrors the official plate-code numbering, but it does not guarantee the exact 5-digit code is an active PTT delivery zone — the tool does not embed the full zone database. Use the province as a checkout sanity check, then confirm serviceability with the carrier. All processing is local.