Intermediaries using the platform can carry out multiple decision in principles (DIPs), share documents and submit full applications with the mutual.
Other lenders such as Accord Mortgages, TSB and Nationwide are already part of the platform and others are expected to join in the coming months.
Martese Carton (pictured), head of intermediary distribution at Leeds Building Society, said: “We are passionate about supporting brokers and making the application process as straightforward as possible.
“The success of our Submissions Brain trial has demonstrated that this is a system which provides tangible benefits to advisers, and we are delighted that we can now go live to whole of market.”
Neil Wyatt, sales and marketing director at Mortgage Brain, added: “Brokers and lenders alike are recognising the tangible difference Submissions Brain can make to the advice process.
“There is no question Submissions Brain saves brokers time and enables them to place cases quickly and smoothly.”