Mexico was never in the NANP. There were special dialing > procedures to reach northwestern Mexico where telephone systems > were installed thanks to US investors, and a special dialing > procedure to reach Mexico city using a dialing sequence that > fit into NANP dialing.
> There was a long transition period in which these areas could > be dialed either NANP style or using Mexico's country code. > Eventually the practice ended when NANPA reclaimed the reserved > dialing procedures for new area codes.
It took certain phone book publishers a while to figure that out.
On a recent stay at a motel in New Mexico, I examined the 2007 edition of the Colvis/Portales/Tucumcari telephone directory (a "Five Star Phone Book" it modestly claimed). It contained the following instructions for calling Mexico:
| Most locations in Mexico can be reached by using the | international diallng (011+) instructions. If you cannot use | international dialing from your telephone, some Mexican cities | can be dialed using special access codes with city codes (see | following list for some City Codes). | | MEXICO CITY dial: | 1 + 90 + 5(the City Code) + local numbers | | NORTHWEST MEXICO dial: | 1 + 70 + City Code (2 or 3 digits beginning with "6") + Local | number
That directory was published in 2007, almost 13 years after 706 and 905 were reclaimed and reassigned as area codes in Georgia and Ontario!
Five Stars indeed.
Neal McLain