Carrier lock vs blacklist confuses new buyback counters and some repair intake desks. They sound related (both can block a clean resale) but they answer different questions:
| IMEI blacklist | Carrier / network / SIM lock | |
|---|---|---|
| Core question | Is this IMEI blocked (e.g. reported stolen / barred)? | Is the device locked to a carrier or unlocked — and if locked, which carrier, does it fit the buyer, how does lock status change pricing, and are there financial obligations? |
| Typical shop pain | Paying out on a device you can’t lawfully/resale-move | Paying out on a locked phone that doesn’t fit the buyer, prices wrong, or still carries financial obligations |
| Check Up plan | Premium: 55 / mo | Premium: 1 / mo |
Explore business checks in IMEI blacklist check for business.
Definitions (US / UK notes)
IMEI blacklist (blocked handset)
A blacklist (or blocked-handset) check asks whether the IMEI appears on relevant blocked-device lists used in your market. Shops care because a blacklisted unit can be unsellable or high-risk inventory even if it powers on and looks Grade A.
Carrier lock (US) / network lock · SIM lock (UK/EU language)
A carrier (or network/SIM) lock check shows whether a device is locked to a carrier or unlocked. If it’s locked, shops need to know which carrier, whether that carrier fits the buyer (you don’t want to be stuck with a phone locked to a carrier that doesn’t matter to the customer), how lock status changes device pricing, and whether there are financial obligations on the device — separate from IMEI blacklist status.
These are separate checks on Check Up Premium: 55 blacklist/mo, plus a carrier lock sample (add-on packs if you need more — these checks are costly).
What shops learn from a carrier lock check
When a device is locked, the check helps answer:
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Which carrier is it locked to?
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Does that carrier fit the buyer? — you don’t want to be stuck with a phone locked to a carrier that doesn’t matter to the customer
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How does lock status change device pricing? — locked vs unlocked often moves the payout or resale number
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Are there financial obligations on the device?
None of that replaces an IMEI blacklist check. Run both when you’re buying.
Shop scenarios
Trade-in / buyback payout
Run functional diagnostics first (or in parallel), then risk:
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Instant Diagnostics + Mobile App Diagnostics
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Device info / account lock signals when available (iCloud/FMiP/MDM and similar)
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Blacklist + carrier lock on Premium before cash out
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Grade + PDF/label + device history report
Free proves diagnostics — Premium includes blacklist and a carrier lock sample so you can try it on real buys. Upgrade when buying is the job.
Repair of a customer-owned device
You may care less about payout blacklist and more about:
- Can we test on a network / Wi‑Fi as needed?
- Are account locks blocking diagnostics or handback?
- Does the customer understand lock vs unlock / SIM limitations after repair?
Still document intake. Blacklist and carrier-lock checks are more critical when your shop takes ownership of the device.
What Check Up includes by plan
| Free — $0/€0/£0 | Premium — US $25 · EU €21.90 · UK £19.90 | |
|---|---|---|
| Device checks | 5 / mo | 250 / mo |
| IMEI blacklist | — | 55 / mo |
| Carrier lock | — | 1 / mo |
| Stations | Multiple (limits workspace-wide) | Multiple (limits workspace-wide) |
| History | 1 month | 6 months |
| Users & roles | — | Yes |
Start Free for diagnostics. Add Premium when trade-in risk checks matter. Optional clean handoff after a buy: secured data erasure — separate from lock/blacklist status.
Quick decision card (print near the till)
| Situation | Check blacklist? | Check carrier/network lock? |
|---|---|---|
| You’re buying the phone (trade-in) | Yes (Premium) | Yes (Premium) |
| Customer-owned repair, staying with customer | Usually optional | If lock / SIM / buyer-fit matters to the job |
| High-value payout | Yes before cash out | Yes before cash out (locked vs unlocked + which carrier + pricing + financial obligations) |
| Diagnostics trial | Start Free for function tests | Start Free for function tests |
Then run function tests either way — locks don’t replace Mobile App Diagnostics. Commercial path: IMEI blacklist check for business. Free diagnostics path: Free phone diagnostics software.
Related pages
- IMEI blacklist check for business
- Trade-in device testing
- Used phone testing software
- Free phone diagnostics software
Questions, answered
Frequently asked questions
What is a carrier lock check?
A carrier (or network/SIM) lock check shows whether a device is locked to a carrier or unlocked. If it's locked, shops need to know which carrier, whether that carrier fits the buyer (you don't want to be stuck with a phone locked to a carrier that doesn't matter to the customer), how lock status changes device pricing, and whether there are financial obligations on the device — separate from IMEI blacklist status. Premium includes a carrier lock check so you can try it on real devices. Need higher volume? Add-on packs are available — these checks are costly, so we don't bury unlimited lookups in the base plan.
Is carrier lock the same as blacklist?
No. Blacklist is about blocked/stolen-style IMEI status. Carrier/network/SIM lock is about locked vs unlocked, which carrier, buyer fit, pricing impact, and financial obligations — separate from blacklist.
Where are blacklist and carrier lock available?
Both are on Premium. Blacklist: 55/mo. Carrier lock: included to sample (add-on packs if you need more — these checks are costly).
How can I try carrier-lock checks and add more?
Premium includes a carrier lock check so you can try it on real devices. Need higher volume? Add-on packs are available — these checks are costly, so we don't bury unlimited lookups in the base plan.
Which should I run first on a trade-in?
Capture function and lock/account signals, then run blacklist and carrier lock before payout when you're buying the device.
Where do I get business IMEI checks?
IMEI blacklist check for business — Premium 55 blacklist/mo + carrier lock sample + diagnostics workflow.
UK wording — network lock vs carrier lock?
Same idea family: network/SIM lock language is common in UK/EU; US shops usually say carrier lock. Check Up's Premium line includes a carrier lock sample (add-ons for more volume). The check still covers locked vs unlocked, which carrier, buyer fit, pricing, and financial obligations.