Any harm in leaving T-Mobile UK Sim Cards in phones until I top them up in UK in Aug?

[snaimon]

Originally Posted by f13dfx

By ACTIVATION do you mean when one TOPS-UP for the 1st time?

Usually, but not always, the EU cards I have purchased, require that you INITIALIZE or ACTIVATE new SIM cards. Sometimes this is as easy as putting the SIM into a phone and allowing the phone to register on the local network. Sometimes the provided asks you to call a customer service number and follow the procedures there. Both the old SIMYO card and the newer SUNSIM required some special action as I described. I cannot remember how the original RIIING or the UM+ activation occurred.

I had some new German T-Mobile cards and I cannot recall they required any special activation at all. I may be wrong.

I cannot speak for your UK cards. Our British friends will have to chime in.

Perhaps there is no user activation required.

Stan