What's included in the minutes bundle? Are there any exit clauses in the service contract? Do you have to rent phones longer than the service contract?
Can you add or remove users within the service contract? Do you have to pay extra for devices or users?
Can the system divert calls to tablets or mobile phones when the access network is down? Are there any restrictions in features when people are remote?
Are all features available to remote workers? Is the call quality consistent?
Are the features the same on the phone, PC, and mobile devices? Do you still have to rely on a telephone?
Does the system support features such as auto attendant, music on hold, automatic call distribution, and call queuing so you never miss a call?
Does the system have features like conferencing, room based collaboration, instant messaging, and presence?
Does the system support iOS and Android devices? Can it support all the productivity features when mobile?
Does the system have web-based user self-administration and allows you to control powerful features from a single web page? Does the service support diagnostics so the service provider can quickly identify any issues that you may run into?