I was using BBM on my IPad then bought an IPhone 5S.

[iMore Question]

BBM is now not recognizing my Username nor email address on my IPad nor IPhone.

 

[BB-JAM215]

You can only use a BBID on one device at a time, but you can switch a BBID from one device to another.

 

[Laura Knotek]

I created two BlackBerry IDs that are different by using two separate email addresses. That way I am able to get all BBM messages on both devices.