The lender has bolstered the team from six to 20 members in an effort to provide advisers with answers when their usual BDM is not available to take calls.
Brokers will still have the same contact number but calls are to be diverted to the telephone BDM team rather than an answer phone.
It means that when a Halifax BDM is in meetings, on holidays or not available to take calls for any other reason, advisers will still get a response.
Early indicators from the changes have proved successful, according to Ian Wilson, head of Halifax Intermediaries.
He told Mortgage Solutions that they are “testing and learning” and the team could be further increased if it the changes prove successful and more support is needed.
Wilson added: “Our focus is always giving brokers a first-class service and making it easier for them to do business with us.
“Growing our telephone BDM team will bolster the support we offer intermediaries through our regional teams across the country, and part of a series of enhancements in 2018 underlining our ongoing commitment to the market.”