Before we can arrange for a replacement SIM to be sent out, we need to deem the existing SIM as faulty.
The most effective way to determine whether the SIM is faulty is through the following steps:
Cross-testing (either or)
- Testing the SIM in an alternative device. Insert the SIM into a known working device, either the same type or a different one (e.g. a mobile phone). Ensure APN settings are appropriately configured.
- Testing the device with an alternative SIM. Insert an alternative known-working SIM into the device. Preferably a SIM with the same set up, belonging to the same network.
By carrying out these troubleshooting steps we can confidently ascertain whether the issues originate from the SIM card or the device.
As a rule of thumb, a SIM card that functions correctly in an alternative device indicates a device-side issue, while a SIM that fails across multiple devices points to a card-side issue.
| What happens? | Likely issue | Action |
| SIM fails in multiple known-working devices | SIM | Replace SIM |
| SIM works in another device | Device | Investigate original device |
| Another working SIM fails in the device | Device | Investigate device |
| Another working SIM works in the device | SIM | Replace SIM |
Note: If the SIM is successfully registered, then physical SIM failure is unlikely. Further investigation should focus on the SIMs provisioning or device configuration.