(1) The Canadian Banks are regulated by the Federal government only, unlike the regulation of banks by either of federal or state athorities in the US.
(2) The Bank Act allows for two types of Banks. Chartered Banks such as CIBC, BMO, BNS, TDCT, & RBC are "Schedule I" banks. The 8 Chartered banks have both a 10% and foreign ownership restrictions. All the "Big Five" Banks have upwards of 1000 branches each and are distributed in every province and in the North. Also in this group are smaller National Bank of Canada, Laurentian Bank of Canada and Canadian Western Bank.
And everyone else is a "Schedule II" bank becaused they are foreign-owned or are holly-owned. These bank are small and often have only one branch. They include banks like Citizens Bank of Canada, AMEX Bank of Canada and HSBC Bank Canada.
(3) However Credit Union are regulated by each province. In Manitoba (where I live), Credit Union are becoming more popular. Many credit unions usually very small and have either one branch or only a handful. As an example Stienbach Credit Union is a one branch operation, but it has over $1 billion in assets. In Manitoba if you take all Credit Unions together they would have the largest market share, with nearly 1 in 4 people as Credit Union members.
(4) Nearly all financial institions in Canada are members of the Canadian Payments Association and the Interac Association. Interac allows Canadians with bank cards to withdrawl money at other banks' ABM across Canada and for direct payment and merchant's POS terminals.