Phone systems get replaced roughly once a decade, which means most people making the decision have never made it before.

Leaving the system you have

Numbers port rather than change, and the old system stays live until the new one is proven. Porting is the step with the longest lead time and the least flexibility, so it is booked first and everything else is planned around it.

What your team actually notices

Calls follow people to mobile and desktop, voicemail arrives as text in email, and hunt groups can be changed by your office manager instead of raising a ticket. Teams users can keep working inside Teams.

The parts nobody asks about until later

E911 address registration per handset, call recording retention if you are in a regulated sector, and what happens to inbound calls when the internet drops. All three are configured before go-live rather than discovered afterwards.

Common questions

Do we keep our numbers?

Yes. Numbers are ported, including main lines and direct dials. The old service is only cancelled once porting has completed.