We looked into this and the guy came out and looked everything over, etc. Ultimately he said it was possible to use the alarm with a cell phone, but that he wouldn't recommend it because it wasn't as much of a "sure thing" as with the landline. There are too many variables and things that can go wrong that make using a cell phone iffy. If the cell network is down or overloaded (as would be the case in a disaster, for example), quality of signal, etc. He advised us to stick with the landline if we wanted to be certain it would work no matter what, so that's what we've done. Of course, YMMV.