I have multiple systems in multiple locations. Historically, everyone has their own account. Can I transfer them all to one email?

Yes, you’ll have to transfer ownership to the person/email you want to use.

If you want to maintain them as ‘separate’ systems, there is the manage your account FAQ. If you want to combine them as a single ‘system’, they need to be on the same subnet, and you would need to factory reset the devices on the systems you want to not keep, then use the ‘add a device’ on the controller when connected to the system you want to keep. Note, this will ‘destroy’ any saved playlists, favorites, alarms, etc, on the devices that you do reset, and copy all of that data over from the system you’re adding these devices to. 

I will not put them in the same network. They will be two separate systems. I just want to put them in one account. Can I have two systems in one account?

Yes.

I will not put them in the same network. They will be two separate systems. I just want to put them in one account. Can I have two systems in one account?

Yes. I have had two systems in two countries under the same account for years.