I'm in Ontario and have 7 kids (various on pt schedules so never more than 5 at one time). The ages are 6 mos, 15 mos, 16 mos, 2 @ 18 mos, 2 @ 23 mos. No, you can never go over that number with children under the age of 10 yrs. Once they hit 10 yrs, they no longer contribute to your head count. Other than that, it's illegal and your insurance won't cover you.