Hi! I'm new here so this might not be the right place to ask this question. I have done some proofreading and editing in the past and I think I would really like to start my own publishing company. One thing holding me back is the cost of ISBN numbers. I have seen that ISBN numbers from Canada are free.

Is there any requirement that ISBN numbers have to obtained in the US to make the book marketable, or can ISBN numbers be obtained through Canada?

Any advice would be appreciated! Thanks!