HSBC retained its position as the nation's best Mortgage Lender, offering the cheapest variable rate mortgages to its existing borrowers, according to a new annual survey. While the bank continued to offer the best-valued mortgages in the market, the report from market research company Defaqto revealed that five of the top ten mortgage lenders were building societies. In fact, both Skipton Building Society and Nationwide made it into the top five of the list, in second and third position respectively just behind HSBC. The results were calculated based on the amount of gross interest payable on a £50,000 interest-only mortgage provided at rates supplied in 2006. Discounting specialist providers and any deals offering loyalty rates, both of which were excluded, the best deal was offered to HSBC customers who paid £3,361.99 for their mortgage over the course of 2007, a whole £532.39 cheaper than the most expensive deal.