You'll need to provide a bit more information and context than that if you want assistance from the Community Forum.
When was it working ok last?
What happened in the meantime?
Is your phone unlocked for use on any network?
Is "no service" the verbatim message displayed on the phone?
What make and model of phone is it?
Was the SIM activated successfully previously?
If you need to contact 48 support about this then see the links in my signature below.
