The lender has also cut rates on its fixed rate and tracker deals to offer two-year fixed rate deals from 3.59% and two-year tracker products from 2.69%.
These rates are exclusively available for appointed representatives with Legal &General, Sesame, Pink Home Loans, Personal Touch Financial Services and Openwork.
Rates for other brokers start at 3.69% and 2.79% respectively.
All the new rate mainstream mortgages come with free valuation and free legal fees for remortgages.
The rates are available via Platform’s panel of intermediary partners and have an arrangement fee of £855 and a £140 administration fee.
Lee Gladwell, director of business development at Platform, says: “This reduction in rates across our mainstream range is good news for brokers, as is our pledge not to increase our tracker rate until base rate 1%.
“Platform is striving to develop a dedicated broker mortgage business that puts IFAs and consumers at the heart of our product and service proposition, enabling them to deliver a fair and personal service. “