The firms are Charles Cameron, Finance Planning Group, First Mortgage and Tenet Lime.
HSBC says this takes the number of brokers to 15 and covers about half of the market.
Those already with access to HSBC’s residential mortgages are: Countrywide, London & Country, Springtide Capital, Alexander Hall, SPF Private Clients, Sesame Limited, Mortgage Advice Bureau, Stonebridge Group, Mortgage Intelligence, First Complete and Openwork.
Tracie Pearce, HSBC’s Head of Mortgages in the UK, said: “The start of the year always gets people thinking about making changes in their life, and getting onto the housing ladder or moving house is a regular new years’ resolution. Making our mortgages available to more intermediary partners will provide a greater choice of deals for house-hunters and those looking to remortgage.”