The structure is certainly intricate. CMAs have, and CGAs will, become associate members of the Institute of Chartered Accountants of Ontario, which has also adopted the business name "Chartered Professional Accountants of Ontario". The ICAO has jealously guarded the CPA designation since their great merger with the Certified Public Accountants Association of Ontario back in 1962. The CPAAO had its own separate governing Act:
They chose to keep that enabling legislation separate, instead of amalgamating the two organizations, by declaring the members of each body to also become members of the other. The Institute still continues to issue regulations specifying the circumstances in which such initials may be displayed, including CPA designations obtained in other jurisdictions.
However, they forgot to get their lawyers to keep tab as to what had been happening over the years. Back in 1990, when the Province issued the Revised Statutes of Ontario, 1990, the final volume contained various schedules detailing repeals, disposition, and the status of various unconsolidated provisions. The last one, Schedule C, is unique, in that it had never been attempted before. Within that Schedule, The Certified Public Accountants Act, R.S.O. 1937, c. 236, was noted as still being in force:
That would have important consequences in 2006. In that year, the Legislation Act, 2006, was enacted by the Legislative Assembly as Schedule F to the Access to Justice Act, 2006:
The crucial provision to note in that schedule was s. 98(3), which declared:
"Every Act listed in Schedule C (Table of Unconsolidated and Unrepealed Acts) to the Revised Statutes of Ontario, 1990, as set out in volume 12 of the Revised Statutes of Ontario, 1990, other than the Acts listed in Column 1 of the Table to this section, is repealed if it has not previously been repealed."
The attached Table did not include the 1937 Act. It was deemed to be repealed on on 25 July 2007. The Province used to have a table online to show that, but it has since been removed
This effectively means that "Certified Public Accountant", and, more importantly, "CPA", were no longer protected professional designations under Ontario law.
In 2010, when the legislation relating to all three professional accounting bodies in Ontario was updated, the Chartered Accountants Act, 2010 came into force, including s. 27, which specified the prohibitions on what designations or related abbreviations were not allowed to non-members of the ICAO.
But does this reinstate the prohibition on using "CPA", or more importantly, "Chartered Professional Accountant"? I think not, as our CGA brethren found out last year when going to the Ontario Superior Court of Justice to attempt to prohibit "CGMA" from being used:
The key paragraphs from this judgment:
 The letter “M” in CGMA would, in my view, qualify as an abbreviation. This is because M is the short form for the word Management. The definition of “combination” suggests each of the objects of the prohibition and “other words and abbreviations” are unified, unbreakable elements. Consequently, CGA is an element and the abbreviation “M” is an element. Thus, the following combinations of these two elements are, in my view, prohibited: “MCGA”, “CGAM”, “C.G.A.M.”, and “M.C.G.A.”.That makes ICAO's position for "CPA" somewhat awkward, to say the least. Could it be argued that inserting "Professional" in the middle of "Chartered Accountant" is of nil effect as well?
 CGMA is not clearly prohibited because the meaning of “combination” does not imply the “M” element can be inserted into the middle of the “CGA” element.
I note that "CPA" and "Chartered Professional Accountant" have been registered as official marks under federal trademark legislation, so the Institute is not without some protection. However, the whole issue will need to be addressed, once the consolidating legislation makes its way through the Legislature after next week's election.