Z10 and 9900

Does anyone know if there is a way to swap between the Z10 and 9900 without changing my AT&T data plan? I know that the Z10 is LTE and the 9900 needs bis, has anyone done this and gotten it to work?

I need a few things for work that are only on the 9900 but love my Z10 and want to use it after work.

Posted via CB10

I switched from my 9900 to Z10 with AT&T and didn't change my plan...

Did you just throw your sim into the Z10 and everything worked fine including LTE? Did you do an upgrade or buy the Z10 outright?

Posted via CB10

...bought outright (gadget geek!), but they had to give me a new SIM. They both use different size SIMs.