Hey there,
We are looking on deciding which MSP suits us best for interacting with our users via iMessage for business. I was wondering how easy or possible it is to switch MSP after selecting one and using it for a live business account. Or is it not possible and you need to recreate an account with a new MSP?
You shall reach to the support team by clicking on the Help button on the top right hand corner of this page https://register.apple.com/messages
No need to create an entirely new account to switch MSPs. Your Messages for Business account registration can be modified to connect to any approved MSP. This is available in the Apple Business Register portal at https://register.apple.com/messages.