Can I keep my help-to-buy Isa even though I've now got a house?

I don’t want to give up my my Halifax Isa as the interest is hard to beat – I’m not sure if I’m breaking any rulesQ I opened a Halifax help-to-buy Isa in December 2015 with £1,000 and have paid the maximum £200 into it every month since. I live in London and recently purchased a house for £500,000, making me ineligible for the government bonus which is capped at houses costing £450,000. I have not closed the Isa as I have accrued £6,000 in re