Parliamentary Budget Office estimates that most TOSI revenues will be generated in Ontario and Alberta
The Parliamentary Budget Officer has estimated that the split income proposals will generate $589M in additional tax revenues for the 2018-19 fiscal year, of which $356 million will go to the federal government. Families in Ontario, Alberta and Quebec would pay $224M (or 63%), $46M (or 13%) and $23M (or 6.5%) of this amount, respectively. This estimate is based on a scenario where all spouses over 24 would not be subject to the new rules:
The rationale behind this scenario is that it is likely that most spouses have assumed some risk in the family business (for example, using the house as collateral for a bank loan to start the business). Therefore, we assume they would pass the reasonableness test and see the dividends they received as being exempt from the TOSI.
Neal Armstrong. Summaries of Govindadeva Bernier and Tim Scholz, “Income Sprinkling Using Private Corporations,” Office of the Parliamentary Budget Officer (with thanks to “Finance Canada officials for their helpful technical discussions”), 8 March 2018 under s. 120.4(3) and s. 120.4(1) - Excluded Amount - para. (g).