Home Information Packs are legally required for anyone that markets their property publicly. There are very few circumstances when you don’t require one, however if you wanted to buy your parents home and no-one else knew it was for sale, then you wouldn’t need one. The same is true if your property wasn’t marketed and you wanted to buy a new build by part exchanging your own (ie to the developer or a company they refer you to) and selling it directly to them.