Quebec’s GRIP is federally based even though it has more restrictive SBD rules
Where a Canadian-controlled private corporation qualifies for the federal small business deduction but not the more restrictive Quebec SBD, the combined (corporate and individual) tax rate on distributed earnings will be 56.42% as contrasted to 56.02% for a Quebec corporation that does not “enjoy” even the federal SBD. This result arises because its earnings are not added to its general rate income pool, whose definition is integrated with the federal rather than Quebec rules, and dividends paid by it thus will also not be eligible dividends for Quebec purposes.
Neal Armstrong. Summary of Hiren Shah and Manu Kakka, "Coming to Grips with Quebec's Lack of GRIP," Tax for the Owner-Manager, Vol. 17, No. 2, April 2017, p.6 under s. 89(14).