Hi Mark, The default setting for MWI is to dial *97, which is the "Check Voicemail" feature and requires a vmbox number and pin. From Advanced Provisioner, under Lines -> Basic -> Voicemail Number; You can change this to **<vmbox_number> EX: **7977. This will be unique for each device. Please note that you will need to enable the "Direct to Voicemail" feature if you have not done so already.