Library and Archives Canada provides ISBNs free of charge to Canadian citizens. Cost Comparison: Single vs. Blocks (US Prices)
Nielsen Book Services handles registration. buying isbn blocks
Bowker (MyIdentifiers.com) is the only official agency. Library and Archives Canada provides ISBNs free of
ISBNs must be purchased from the official agency in the country where your publishing business is physically located. buying isbn blocks
Thorpe-Bowker serves these regions.