During my time at Microsoft I did not have a chance to migrate any customer since Microsoft Calling plan was not available for Asia Pacific.
The list of articles here are all my experiences with migrations to Teams calling plan and also from Teams calling plan to Telco porting. I searched in several places for documentations by individuals about the process and how to proceed, and I did not have much luck in my search. Hence, I thought why not I give back to the community about my daily hustle in summary.
Number porting can be very simple to complex, this completely depends on the environment, the type of numbers available in that environment, their usage, and the level of knowledge the customer has about their own environment. Prior to submitting any order (be it Microsoft or any Telco around the world), number planning is required, and the entire process can consume many hours.
Porting request submission
Porting request(s) can be submitted from two locations:
1. Teams Admin Center (TAC) > Voice
2. Access via PTN portal - https://pstnsd.powerappsportals.com/