Probably not even the chancellor yet
Nah, sounds like it will be based on your 'bottom line' - the total net income, you incomings minus all the outgoings. I too think there will be a few naughty people caught out by this, not declaring cash jobs, putting through loads of expenses etc to keep their tax bill down.
It's a welcome intervention, but end of June is estimated date for payments... I wonder how many will go under.
I think the above will also inadvertedly (or perhaps deliberately) 'catch out' company directors who pay themselves a low salary but top up wages with dividends (the company has already paid corporation tax at 19% on the dividends, and then those dividends have additional tax on them too, so it's not exactly a tax fiddle), me included within this.
It's an uncertain time for all in business, and with all the other shit going on in my life, pretty much the only thing stopping me jumping off a bridge right now is my bike and the fact that I'm extremely lucky to live in a spot where I can get out on the moors without needing to take the car.