I just bought a Nokia Lumia 520 at Walmart and the sales rep told me it would be possible to activate it on my existing postpaid account... tried to do a self serve phone swap and it says the sim# is invalid. Is it possible to activate this phone on my existing postpaid account?
The phones are identical between prepaid and postpaid. The only difference is the sim cards. Does this phone take a different size of sim card than your previous phone? If not, just move the sim from the old phone to the new one. Is the sim card you got with the new phone a prepaid sim or a postpaid sim? Because prepaid sim cards cannot be activated on a postpaid account.