The idea behind a business account with sub-accounts is simple. Think of your main account as the central hub for all income. From there, you distribute your money manually or automatically into different pots. That way, you easily separate fixed costs from your budget for new investments.
It saves valuable time in bookkeeping especially, because you assign transactions right at the source. You see at a glance how much you've spent in each area. And at the end of the month, there are no receipts left to sort. That transparency protects you from nasty surprises like unexpected tax bills.
