Something's funky here, but maybe it's my understanding of you.

My cordless phone (Siemens) is kinda like yours, with one useful addition: it allows multiple entries of local area codes. So for metro Denver, CO, that means (303) and (720). But our LATA *requires* 10-digit dialing now, so all local numbers captured to the handset 's phonebook have 10 digits already. Long distance numbers come in without prepending the "1" but that's a simple "Edit" before "Save."