The three firms have agreed to go through a training system which will inform consumers about the protection available to them on their savings and current accounts.
The online training is offered by the Financial Skills Partnership as part of firms' employee training.
The new scheme is being introduced ahead of new Financial Services Authority rules compelling banks and building societies to inform consumers about which deposit guarantee schemes apply to their money.
Firms will be required to display posters and stickers promoting FSCS and provide information on their website.

Mark Neale, chief executive of the FSCS, said: "The banking crisis showed how important it is for consumers to have clear information about FSCS protection.
"We have been working with major firms for the last 18 months to get them to go the extra mile in building awarenesss about the protection which exists for consumers.
"Three firms are initially taking up the training and we are delighted to have their support. It is important for other firms to follow their lead."
Sarah Thwaites, deputy chief executive of the Financial Skills Partnership, said: "This training module will not only help to fulfill regulatory requirements, it will also up-skill staff in a way that sends out a positive message about advances being made in the finance industry."