@StephenC
Some things to try:
Manually search for another network
Reboot the phone
Turn off 5g in network settings
If you have an iPhone change your data APN to "mobile.o2.co.uk"
If still not working then contact O2 to remove the Roaming bar on your account.
If you message O2 on Facebook ( https://o2uk.co/O2CFB) , Twitter ( https://o2uk.co/O2CTW) or Instagram ( https://o2uk.co/O2CIG) , they should be able to help you with this.
I have no affiliation whatsoever with O2 or any subsidiary companies. Comments posted are entirely of my own opinion. This is not Customer Service so we are unable to help with account specific issues.
Please select the post that helped you best and mark as the solution. This helps other members in resolving their issues faster. Thank you.
