T-Mobile voicemail is not like your old answering machine. Unanswered incoming calls are rerouted by the T-Mobile network to your voicemail port. All of your incoming voicemail and your voicemail greetings are taken care of on the network and not in your phone. When you check your voicemail with your phone you are actually dialling into the T-Mobile network and going to your private voicemail port. While your voicemail service is active, every unanswered call goes to your voicemail and you incur charges for an incoming phone call. If you are roaming or on international rates, those are the rates you will be charged for these unanswered incoming phone calls.
Disconnect or suspend your voicemail service by calling T-Mobile customer service from your T-Mobile phone by dialling 611. Call customer service from another phone by calling 1-877-453-1304.
Explain to the customer-service representative that you want to disconnect your voicemail service.
Clarify your request to the customer-service representative by telling her whether this request is for a permanent disconnection or if it will be a temporary suspension of service.
Confirm that T-Mobile has disconnected your voicemail service, after you have completed your phone call with T-Mobile, by dialling your T-Mobile phone number from another phone and making sure that your call is not picked up by your voicemail service. If your voicemail service has been disconnected, the phone will continue to ring.
While your phone may offer call-forwarding options, which allow you to forward the incoming call to another phone number instead of to voicemail, if you do not supply the alternative phone number the T-Mobile network will send incoming calls to your voicemail. Only T-Mobile customer service can successfully disconnect your voicemail.