Three SIM Card Not Detected on Xiaomi
What this means: Three SIM Card Not Detected on Xiaomi means this feature is not working correctly. Follow the steps below to diagnose and fix the issue on your Xiaomi with Three.
- Power off completely before reinserting SIM
- Clean SIM contacts with dry cloth — avoid liquids
- Try SIM in another device to test if SIM itself is faulty
- Contact carrier for SIM replacement if issue persists
ℹ️ About Three — SIM Card Not Detected
Three operates on the Three (own network). Three's Feel At Home roaming covers 71 destinations. iD Mobile and SMARTY also use Three's network.
Known Xiaomi considerations: 5G coverage mainly in city centres. eSIM supports dual-SIM on compatible devices.
- Support number: 333 (from your Three SIM)
- Support page: https://www.three.co.uk/support
- Network status: Check Three network status
Fix Three SIM Not Detected on Xiaomi
Check device settings
Go to Settings → SIM cards & mobile networks and verify all settings are correct.
Toggle Airplane mode
Enable Airplane mode for 30 seconds then disable — resets network connection.
Restart device
Power off completely, wait 10 seconds, power back on.
Reinsert SIM
Remove and reinsert the SIM card to refresh network registration.
Check APN settings
Go to Settings → SIM cards & mobile networks → [SIM] → Access Point Names and confirm APN is set to three.co.uk.
Reset network settings
Go to Settings → Connection & sharing → Reset Wi-Fi, mobile & Bluetooth to clear corrupt network configuration.
Update software
Go to Settings → About phone → MIUI version → Check for updates and install any pending updates.
Contact Three
Call Three on 333 if issue persists after all steps above.
⚡ Three APN Settings Reference
| Setting | Value |
|---|---|
| APN | three.co.uk |
| Username | (leave blank) |
| Password | (leave blank) |
| MMSC | http://mms.um.three.co.uk:10021/mmsc |
| Three Support | 333 |
Frequently Asked Questions
What is the best way to fix SIM Card Not Detected on Xiaomi?
Start by toggling Airplane mode, then restarting the device. If that doesn't work, check the APN at Settings → SIM cards & mobile networks → [SIM] → Access Point Names — confirm it is set to three.co.uk. If still failing, reset network settings and contact Three on 333.
Do I need to contact Three to fix this?
Most SIM Card Not Detected issues on Xiaomi can be resolved by following the steps above without contacting Three. If the problem persists after all steps, call Three on 333 — they can check for account-level or network-side issues.
Will a network reset help with Three on Xiaomi?
Yes — a network reset at Settings → Connection & sharing → Reset Wi-Fi, mobile & Bluetooth clears corrupted APN settings and network configurations. Remember to note your Wi-Fi passwords first as they will be cleared. Re-enter the Three APN (value: three.co.uk) after the reset.
📞 When to Call Three
If all steps above have not resolved the issue, call Three on 333 (free from Three). Ask them to check data provisioning, account status, and any local network events.