When I ordered my 8700 I was told that I will also get a new sim card. I asked about if I should use the old onr from my 7290 or the new one. I was told the new one is a 64K sim card and the old one is 32K and that both would work with no problem. I do not know what the difference is between the new and old sim other than one has twice the memory storage capacity. I am going to try the new one tonight when I setup the 8700 that was delivered today.