Unlock guide
A Samsung Galaxy A51 is locked the same way any Samsung handset is: the carrier that sold it holds a record against the IMEI, and the device refuses every other SIM until that record changes. This page shows how the model is identified in the TAC register, what kind of lock it uses, and which of our services apply.
The TAC — the first eight digits of the IMEI — is how the register knows which model a handset is, and it is what every unlock and warranty service actually queries. Our register holds 157 TAC ranges under this model name:
| TAC prefix | Look it up |
|---|---|
35022043 | run the lookup |
35047567 | run the lookup |
35067889 | run the lookup |
35101718 | run the lookup |
35108811 | run the lookup |
35121615 | run the lookup |
Dial *#06# to read the IMEI, then compare the first eight digits. Not listed? The lookup will still resolve the model if the range is filed under a different name.
The register dates this model to 2019, which decides how it is locked: handsets of that generation and market follow the rules described below.
Samsung devices can be locked two different ways. Older and mid-range models prompt for an NCK / MCK code that is derived from the IMEI and typed on the keypad. Flagships from roughly 2020, and all US carrier variants, are locked server-side like an iPhone and have to be released by the carrier instead.
On a Samsung Galaxy A51 the practical test is simple: insert a SIM from a different network. If the phone asks for a code, it is code-locked. If it refuses with “SIM Not Supported” or a carrier-lock notice, it is server-side locked and has to be released against the IMEI. If it just works, it is already unlocked.
| Service | Price | Type |
|---|---|---|
| USA | Canada Blacklist Check - iPhone. Samsung, Pixel & Generic | $0.03 | Blacklist |
| USA+GSMA/CA Worldwide Blacklist+Reason Check - iPhone & Generic | $0.04 | Blacklist |
| Verizon | Visible Blacklist Check Pro - iPhone, Samsung, Pixel & More | $0.04 | Blacklist |
| Samsung Knox Guard Lock Check | $0.05 | device check |
| US AT&T Blacklist Check - iPhone & Generic | $0.05 | Blacklist |
| Samsung Identification Report - OS+Carrier etc. Check | $0.06 | Carrier |
Brand-level services from $0.03 – $0.06. The carrier-specific tier is on the carrier guide and on each service page.
Unlock prices depend on the carrier and the model generation, so the same handset costs different amounts depending on who sold it. These are the carriers we hold a service for:
TAC data from the register we query for /tac. Last updated 2026-10-28.