BM Solutions will accept portfolio buy-to-let applications after the new underwriting standards come into force on 30 September.
The lender will launch a national broker workshop programme with face-to-face workshops up and down the UK from 21 August to help intermediaries understand the changes.
BM Solutions will not change its practices for landlords with three or fewer buy-to-lets.
Phil Rickards, head of BM Solutions, said: “A continuous wave of changes in the past few years has led to added layers of complexity in the buy-to-let market.
“We have worked hard to keep our ethos of making things simpler, and whilst the new PRA standards will require some more information at the time of application, I’m confident that our new proposition will support brokers to continue writing good quality portfolio business, backed by the award-winning service on which we remain focused.
“Being able to support both small and portfolio landlords with our tailor made proposition is a key part of our ongoing commitment to the market.
“I would strongly urge brokers to contact their BDM to secure a place at our upcoming workshops where we will unveil full details of our criteria.”
Under Prudential Regulation Authority rules firms must display a ‘specialist underwriting approach’ for borrowers with four or more buy-to-lets from 30 September 2017, scrutinising the borrower’s full portfolio of properties and outstanding mortgages in addition to the standard assessment.