My iPhone 13 Spain will not Data roam abroad.

[Howard_Leigh]

 My O2 SIM has plenty of data left but in Spain it will NOT do data roaming even though switched on. With Wi-Fi it’s fine. If I put my spare Plusnet SIM in my iPhone roams happily. Put my O2 SIM back it stops data roaming. How do it correct this?!’

[Enlli · Accepted solution]

You could start by trying this: change your data apn to "mobile.o2.co.uk"

Guide: Roaming MegaGuide  May also be useful

[Howard_Leigh]

Thank you. That worked especially when I replaced all the relevant settings to mobile.o2.co.uk

I now have 5G!!