Unlock code calculator

Phone family

IMEI

Master code (engineering / “backdoor” code)

The master code is a 15-digit number derived from the IMEI. It is used to unlock DCT3/DCT4 phones when the lock code is lost. It does not work on 1100, 1110, 1600, 2100, 2300, 2600, 2650, and/or BB5 phones.

—

Enter 15 digits above.

Phone model

Network / operator the phone is locked to

…or enter the network code by hand

Digits 1–5 depend on the “box serial”; digits 6–15 do not. If a code you know is good shares its last ten digits with the result below but not the first five, the algorithm is fine and only this setting differs. Paste that code on the right and the correct box serial is filled in for you.

The field pre-fills with the selected model’s suggested value. If that fails, the dropdown lists every documented box serial, most-likely-first — try 033820 (“v2”, the usual answer), then 034144 (“Griffin new”). Provenance for each value is in data/box_serials.json.

DCT4 box serial (6 digits)

Recover it from a known-good code

DCT2 needs the extra lock fields as well. Leave the defaults if you do not know them.

Lock selector

MCC+MNC (5 chars)

GID1 (4 hex)

GID2 (4 hex)

MSIN (10 hex)

Model / variant

Result

Lock	Code	Enter on the phone