How Chinese ID region codes work
What the first 6 digits mean, and what region lookup can and cannot tell you.
An 18-digit resident ID starts with a 6-digit administrative division code for the registered province/city/district.
Those 6 digits alone are enough for a region lookup; a full number also yields birth date, gender sequence and a checksum.
The region is hukou registration at issue time — not current address, and not proof of identity.
Some historical divisions were renamed or removed; older names or city-level matches can appear.