Step 1. Dial 1-805-MESSAGE (1-805-637-7243) from any landline.
Step 2. Press * (Star) key
Step 3. Enter your 10-digit T-Mobile phone number
Step 4. When prompted, enter your password.
For a visual representation of T-Mobile VoiceMail shortcuts please refer to the following PDF diagram.

This tip works with both postpaid and prepaid accounts.
Other possibility is to enter the area code and prefix of your phone number, followed by 9999. For example, if your phone number were (954) 542-1234, you would dial (954) 542-9999.
ReplyDeleteSee more at: http://support.t-mobile.com/knowbase/root/public/tm20304.htm