REI BlackBook currently offers phone numbers across all 50 states in the United States as well as all major cities & provinces in Canada.
United States Phone Numbers
Within the US, you are able to secure phone numbers in almost all area codes. However, there are some exhausted area codes in major metropolitan areas that REI BlackBook is unable to offer such as (602) in Phoenix and (212) in New York. Relatively new and/or future area codes may have a limited inventory as well. To see what numbers are available check out How to Add Phone Number.
Canadian Phone Numbers
Canada also has a few exhausted area codes in major metropolitan areas that REI BlackBook is unable to offer such as (416) in Toronto, (905) in Ontario and (403) in Calgary.
While REI BlackBook does its best to maintain a broad selection of area codes at all times, sometimes you may encounter an issue where the area code you're looking for is temporarily out of stock. If this ever happens, we recommend using overlay area codes as a workaround.
An area code overlay is a North American area code that is assigned to the same numbering plan area (NPA) as at least one other area code. Overlay codes are determined and regulated as part of the North American Numbering Plan to increase the number of available telephone numbers in a province, state or region
You may find the complete list of area code overlays here.