"The subscriber you have dialed is not in service"

The subscriber you have dialed is not in service, if you feel you have recieved this message in error please hang and try your call again later. Message mo972

Does this mean that the person has disconnected there cellphone or shut off service, from what I gather from T-mobile and the website it's either b/c of tower problems ie (switches) or signal strength but I want to be sure! Please help me out here ty.

when i get that its because the party im trying to reach has run out of minutes

Well this subscriber ain't prepaid they are post paid (monthly) so it's not b/c their out of minutes! Do you have any other suggestions since you now klnow that this person is Post-Paid and not Prepaid!

The person no longer has service with the provider.

I get it when my gf has her phone turned off and she is not in a tmobile zone.