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🚀 Activating Your Physical OnSim SIM

ONSIM
Updated

Welcome to ONSIM! If you have received a new physical SIM card, follow the steps below to get connected.

Note: This guide is for new services only. If you are activating a replacement SIM for an existing number, please refer to our [SIM Replacement Activation Guide] instead.

 

Step-by-Step Activation

  1. Go to the Activation Page: Visit onsim.uk/activate and log in.

  2. Select Activate: Click Activate SIM from the main menu.

  3. Enter SIM ID: A box will appear. Carefully enter the last 6 digits found on the back of your physical OnSim SIM card.

  4. Automatic Processing: As soon as you type the 6th digit, the system will verify the ID. If it matches our records, the activation process starts immediately.

  5. Confirmation: A success message will appear on your screen once the process is complete.

✅ Post-Activation Checklist

Once you receive the confirmation email that your replacement is active:

  • [ ] Insert the SIM: Place the new SIM into your device.

  • [ ] Reboot Your Device: This is essential to help the new SIM register with the network for the first time.

  • [ ] Check Your Settings: Ensure VoLTE (4G Calling) and Wi-Fi Calling are still toggled ON in your phone's settings.

  • [ ] Verify Data: If your plan includes data, check that your internet is working. If not, refer to our [Data Settings Guide].

    A full guide on how to do this can be found here. 

⚠️ Troubleshooting On-Screen Errors

If you encounter an error message, here is how to resolve it:

Error: "404 Not Found" (When clicking Activate SIM)

This typically means there are no unactivated physical SIMs currently allocated to your account.

  • The Fix: If you have an unactivated SIM in your hand but see this message, please email support@onsim.uk so we can manually link it to your profile.

Error: "404 Not Found" (After entering the 6th digit)

This occurs if the digits entered do not match the SIM ID we sent out to you. To fix this, you must reset your session:

  1. Logout: Click the Person Icon (top right) and select Logout.

  2. Restart: Visit onsim.uk/activate and log back in.

  3. Re-enter: Select Activate SIM and carefully type the 6 digits again.

Still having trouble?

If the numbers are definitely correct but you are still seeing an error, our team is ready to help.

  • Email: support@onsim.uk

  • Pro Tip: Attach a photo of the back of your SIM card to your email to help us speed up the investigation!

 

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