In the Chrestomanci books, witches and wizards are prevented from running roughshod over ordinary folk by the people who work in Chrestomanci Castle, headed by the nine-lives enchanter titled Chrestomanci. Gwendolyn and Cat Chant are invited to live at the castle but find they don't like it in Charmed Life. Christopher, in The Lives of Christopher Chant, is taken in after he blows the roof off his tutor's house. He hates it too, and all of them are protecting secrets.
Cats figure largely in both books. Gwendolyn turned Cat's violin into a cat, thereafter called Fiddle, because she said that's what his playing sounded like. Christopher brings back a sacred cat named Throgmorten from the Temple of the Living Asheth, only to be followed from that other world by the Living Goddess herself.
I've always been wary of books marketed as being like best sellers, but when I read Harry Potter and the Sorceror's Stone I was reminded immediately of The Chronicles of Chrestomanci stories. Wynne Jones did not write a chronological sequence like Rowling but there are more books in which Chrestomanci makes an appearance: The Pinhoe Egg, Conrad's Fate, The Magicians of Caprona, and Witch Week, the last two collected in Volume II of the Chronicles.