Registering a name does NOT give you EXCLUSIVE use of it.  Exclusive use of a name is available only through incorporation of the business.  The Ontario Business Names Act does not prohibit registration of identical names.  However, if you decide to use the same or similar name of another business, it could result in confusion or a possible lawsuit, particularly if the business is located in the same city.  The person registering a name assumes full responsibility for any risk of confusion with an existing business or corporation.