12D Numbering System / Dialing Plan

10D/11D Dialing Plan Gap
Where 10D dialing is used, the fourth digit is never 0 or 1. The first digit of the 10D number is also never 0 or 1. Also, due to being reserved for expansion, the second of the 10D is never a 9. There are other restrictions due to three digit n11 codes and other concerns, but the major gaps available to be exploited by an expansion dialing/numbering plan that is permissive rests in those three rules.

It would be convenient to have a recognizable pattern, such as placing a '9' between the first two digits so that distant callers would be able to know the new NPAX (x for expanded) number by simply knowing the old 10D number and a rule.

That poses a series of problems:
  1. npa-nxx-xxxx -> n9pa-0nxx-xxxx would be the transition
    Having every 4D exchange be a 0nxx code would not easily lead to 8D dialing in overlays. Therefore alternative plans must be presented for overlay areas. As 10D is required in overlay areas, the 7D to 8D proposal does not apply. Separate 10D to 8D migrations would need to be done. NPAX's would be as geographically spread as NPA's - no improvement
    One of the complaints of the current system is one can make an international call in the same manner as they call the next state. Without a code list or a memory those 'expensive' codes would remain just as stealthy as they are today. Therefore in migration to 4D NPAs I'd like to see non-US and Canada codes placed in a special series. (Canadian codes addressed below.) Small nations would receive a huge numbering space, as big as Mexico's
    Do small nations that could live in a handful of exchanges deserve 80,000,000 numbers (nxxx-xxxx)? On a related issue, do they need to be forced from 7D to 8D? I believe there is room in the NANP for clearly defined differences in dialing patterns in different countries.
    Which brings me to: Canada remains spread all over the NANP
    Canada has expressed it's desire to remain with 7D and 10D dialing and break away from the 12D numbering plan as much as possible. I believe their needs can be met without harming the rest of the NANP by granting Canada +1 00 as their unique numbering space.
  2. Special Interest Groups
    How would you like an 800 number that is now 8900? Toll Free subscribers have shown great interest in keeping their numbers, but having various ranges of toll free such as 8900, 8988, 8977, 8966, 8955, 8944, 8933, and 8922 is not uniform. These numbers would have to work 'outside' an "insert 9" plan.
I do want to take advantage of the n9x reservation, but I believe we need to take advantage of one of the gaps in the dialing plan to take full advantage.

[Introduction] - [Moving 7D -> 8D] - [12D Plan] - [Transition] - [Complete Review]