Knowing how to check if a phone is unlocked is important before buying, selling, trading in or processing a used device. An unlocked phone can usually work with SIM cards from different mobile networks, while a network-locked phone may only work with one provider until the network unlocks it.
This guide explains how to check if a phone is unlocked on iPhone and Android. It also covers what “network-locked” means, how SIM testing works, why a factory reset does not unlock a phone, and why trade-in teams should treat unlock status as one part of a wider used-phone check.
For an individual seller, unlock status can affect whether a buyer can use the phone with their own SIM. For a recycler, refurbisher or trade-in team, it can affect valuation, device routing, listing accuracy and return risk.
In the UK, Ofcom banned mobile companies from selling locked handsets from 17 December 2021. However, older devices, imported devices and previously sold handsets may still need checking before they are described as unlocked. Ofcom confirmed the locked-handset sales ban came into force on 17 December 2021.
What does it mean if a phone is unlocked?
An unlocked phone can usually be used with SIM cards from different mobile network providers, provided the device supports the network and the SIM or eSIM has been set up correctly. A network-locked phone is restricted to a particular mobile network until the network provider unlocks it.
This is different from a screen lock, passcode lock, Activation Lock or Google account lock. Those are separate issues. A phone can be network-unlocked but still account-locked, blacklisted, damaged or not ready for resale.
How to check if an iPhone is unlocked
Apple gives a clear method for checking whether an iPhone is unlocked. Open Settings, tap General, then tap About. If No SIM restrictions appears next to Network Provider Lock, the iPhone is unlocked. Apple lists this as its official way to check iPhone unlock status.
Use these steps:
- Open Settings
- Tap General
- Tap About
- Find Network Provider Lock or Carrier Lock
- Look for No SIM restrictions
If the iPhone does not show “No SIM restrictions”, or if it shows a network lock message, contact the network provider before describing the device as unlocked.
How to check if an Android phone is unlocked
Android phones vary by manufacturer, model, network and software version, so there is no single universal menu that works for every Android device. In practice, the most common check is to insert a SIM from a different mobile network and see whether the phone accepts it.
A practical Android check is:
- Turn off the phone
- Insert a SIM card from another mobile network
- Turn the phone back on
- Check whether the phone connects to the network
- Make a test call or check mobile data where possible
If the device shows a message such as “SIM not supported”, “network locked”, “SIM network unlock PIN” or asks you to contact a carrier, it may be locked. Vodafone’s device guidance for Pixel phones also uses the practical method of inserting a SIM from another operator and checking whether the phone reports that it is SIM locked. Vodafone’s Pixel guidance explains this SIM-based lock check.
Can a SIM test prove a phone is unlocked?
A SIM test is useful, but it is not perfect in every situation. If a phone accepts a SIM from a different network and connects normally, that strongly suggests it is unlocked. However, connection issues can also happen for other reasons, such as poor signal, incompatible network bands, SIM problems, account issues or eSIM setup problems.
For that reason, a SIM test should be treated as practical evidence, not the only possible source of truth. Where the device value is high or the result is unclear, it is sensible to confirm with the network provider or use a more controlled trade workflow.
What does network-locked mean?
Network-locked means the phone has been restricted to work with one mobile network or carrier. If a user inserts a SIM from another network, the phone may reject the SIM, ask for an unlock code or fail to connect normally.
This matters before resale because buyers often expect a used phone to work with their own provider. If the device turns out to be locked, the buyer may return it or raise a dispute because the listing did not match the device.
For trade-in and resale teams, network lock status should be recorded clearly. If the phone is locked, the device may need a different value, route or description.
Does factory reset unlock a phone?
No. A factory reset does not normally remove a network lock. A factory reset clears user data and returns the phone to default settings, but it does not usually change whether the device is restricted to a mobile network.
This is one of the most common mistakes in used phone resale. A phone can be reset, wiped or cleared for setup and still be network-locked. It may also have other issues, such as account lock, blacklist status, battery faults or damage.
What is the difference between network lock and account lock?
Network lock and account lock are different issues.
- Network lock: the phone may only work with one mobile network or carrier
- iPhone Activation Lock: the device may still be linked to an Apple Account and cannot be set up by a new user until removed properly
- Android FRP/account lock: the phone may require the previous Google account after reset
- Screen lock: the phone may still require a passcode, PIN, pattern or biometric unlock
A phone can be unlocked from a network but still blocked by an account lock. Therefore, trade-in teams should check both network status and account/reset readiness before resale.
Can an IMEI check show if a phone is unlocked?
Some services may provide device or network-related information using an IMEI, but unlock status should not be treated as a simple universal IMEI answer in every case. The safest approach depends on the device and the evidence available.
For resale or trade-in, a stronger process combines:
- iPhone settings where available
- different-network SIM testing where practical
- network-provider confirmation if needed
- IMEI and status checks
- functional device testing
- clear notes in the device record
This reduces the chance of selling or valuing a phone incorrectly.
What should you do if a phone is locked?
If a phone is network-locked, the correct next step is usually to contact the network provider it is locked to. Apple advises users who want to unlock an iPhone for use with another network to contact their network provider. Apple’s support guidance explains that only the network provider can unlock the iPhone.
Before selling or trading in a locked phone:
- find out which network it is locked to
- contact the network provider for unlocking instructions
- avoid advertising it as unlocked until confirmed
- tell the buyer or trade-in provider if it remains locked
- keep confirmation if the network unlocks it
In a trade environment, locked or unclear devices should be held for review rather than treated as normal unlocked stock.
Why unlock status matters before selling or trading in
Unlock status affects buyer expectations. If a buyer expects an unlocked phone and receives a network-locked device, they may not be able to use it with their SIM. That can lead to a return, complaint or dispute.
For businesses, unlock status can affect:
- trade-in value
- resale listing accuracy
- sales channel suitability
- customer confidence
- return risk
- device routing
However, unlock status is only one part of the check. A phone may be unlocked and still fail other resale checks.
Unlocked does not mean resale-ready
An unlocked phone is not automatically ready to sell. It may still have a poor battery, broken microphone, damaged screen, account lock, blacklist issue or personal data left on it.
Before resale, teams should also check:
- device identity and IMEI
- blacklist or network block indicators
- lost or stolen status indicators
- account or activation locks
- screen, battery, camera, audio and port function
- data erasure result
- cosmetic grade and final description
This is especially important for recyclers, refurbishers and trade-in teams that process devices at volume.
How MobiCode supports used phone checks
MobiCode helps businesses check and process used phones more consistently. Unlock status is one part of the wider device due-diligence process.
- Device checking: MobiCode CHECK supports due diligence before buying, processing or reselling used phones.
See: MobiCode CHECK - IMEI and status checks: MobiCHECK helps teams identify risk indicators before devices enter stock.
See: MobiCHECK - Device testing: MobiCode TEST helps teams test used phones more consistently before resale.
See: MobiCode TEST - Connected workflows: MobiONE helps link checks, tests, wipe results and device records in one operational process.
See: MobiONE - Secure data erasure: MobiWIPE supports clearer data erasure workflows before devices are released.
See: MobiWIPE
For businesses, the benefit is consistency. Each check should help the team make a better decision about the handset, not just tick a box.
Common mistakes when checking if a phone is unlocked
Most unlock-status mistakes come from assuming rather than checking. That creates avoidable resale problems.
Common mistakes include:
- assuming a factory reset means unlocked
- advertising a phone as unlocked without evidence
- testing only with the original network SIM
- confusing network lock with account lock
- ignoring lock messages during setup
- forgetting to record the result
- treating unlock status as a full device check
Fortunately, these mistakes are easy to reduce. A simple, consistent workflow gives sellers and trade teams better evidence before the device is listed or valued.
Commercial takeaway: how to check if a phone is unlocked
To check if a phone is unlocked, use the device settings where possible or test the phone with a SIM from another network. On iPhone, Apple says “No SIM restrictions” next to Network Provider Lock means the device is unlocked. On many Android phones, inserting a SIM from another operator is the most practical check.
Before selling, buying or trading in a phone, remember that unlocked does not mean fully checked. The safer approach is to confirm unlock status, check the IMEI, test the device, remove account locks and make sure data has been handled properly.
A practical example before selling a used phone
A seller wants to list an older smartphone as unlocked. Before doing so, they check the iPhone settings or insert a SIM from another network on Android. If the evidence supports the unlocked claim, they can describe the phone more accurately.
However, a trade-in team should still check the IMEI, account status, screen, battery, cameras, audio, ports and data erasure result before assigning a final value. Unlock status is useful, but it is only one part of a proper resale check.
FAQ: how to check if a phone is unlocked
How do I check if my iPhone is unlocked?
On iPhone, open Settings, tap General, then About. If “No SIM restrictions” appears next to Network Provider Lock or Carrier Lock, Apple says the iPhone is unlocked.
How do I check if my Android phone is unlocked?
On Android, the most practical check is usually to insert a SIM from a different network. If the phone connects normally, it is likely unlocked. If it asks for an unlock PIN or says the SIM is not supported, it may be locked.
Does factory reset unlock a phone?
No. A factory reset clears user data and settings, but it does not normally remove a network or carrier lock.
Are UK phones sold unlocked?
Ofcom banned UK mobile companies from selling locked handsets from 17 December 2021. Older devices, imported devices and second-hand phones may still need checking.
Is an unlocked phone ready for resale?
Not automatically. An unlocked phone may still need IMEI checks, blacklist checks, account lock checks, functional testing, grading and secure data erasure before resale.