Both the enterprise's and the applicant's. Nationals of a single treaty country must own at least half the business, and the person applying must hold that same nationality. A split that leaves Canadian owners below half cannot be rescued by the applicant's Canadian citizenship alone.
Count the shares first, then check the passports against them
The order of analysis matters because it saves wasted work. Begin with the capitalization table as it will read after closing, group the owners by the citizenship each actually holds, and ask whether any one treaty country reaches fifty percent. In Hilde's case Canada reaches forty-five and stops.
Her brother's citizenship reaches one hundred, because she holds it as well, and that is the treaty the case has to be brought under. Had she held only Canadian citizenship, the options would be to shift five percent of the shares or to abandon the category. Two related points arise regularly.
Corporate owners are looked through to the individuals behind them, so inserting a Canadian holding company changes nothing unless the individuals behind it are Canadian nationals. And a change in ownership after the visa is issued can undo the qualification, which is why later share transfers to non-nationals should be reviewed before they are executed rather than after.