Nationwide Building Society is launching a new loyalty initiative for customers converting their main residence into a buy-to-let.
Customers must take out the mortgage with the society's subsidiary The Mortgage Works (TMW), while using a Nationwide mortgage to buy a home to live in.
At the same time, TMW is also launching a new set of dedicated loyalty let-to-buy products.
Customers can now apply simultaneously for a let-to-buy mortgage on their existing property with TMW and the onward residential mortgage for their new property through Nationwide.
They will be also rewarded with a £250 loyalty cashback.
This is the first time Nationwide has offered a dual-branded proposition combining both its residential mortgage arm and TMW.
Paul Wootton, head of specialist lending, said: "Nationwide is taking a joined-up approach to helping home movers turn their existing home into a buy-to-let, while purchasing a new home in which to live.
"We are making it easier and more flexible for our customers to complete the process of securing two different types of home loan at the same time, helping those who may wish to live elsewhere but want to turn their existing property into an investment opportunity."
Customers will be able to apply for a new residential mortgage with Nationwide of up to 85% LTV when applying for a TMW let-to-buy loan.
TMW's new let-to-buy loyalty products, and the new Nationwide process, are available only through intermediaries and will be available to both existing mortgage customers and those new to Nationwide.
In addition, all TMW let-to-buy mortgage customers will receive a free standard valuation as part of a revised range.
David Hollingworth, associate director at intermediary firm London & Country, said: "A move to a new property can often be the point when an owner makes the decision to become a landlord.
"Linking the two sides of the let-to-buy coin makes sense and should give brokers and their customers the option of a more joined up solution with added cost incentives."
New TMW let-to-buy products:
Two-year fixed rate with £995 fee, available up to 65% LTV at 2.99%.
Two-year fixed rate with £995 fee, available up to 75% LTV at 4.09%.
Five-year fixed rate with £995 fee, available up to 65% LTV at 3.99%.
Five-year fixed rate with £995 fee, available up to 75% LTV at 4.49%.