The minimum size for Premier loans is now £500,000, up from £350,000.
When the Premier service was launched in 2014, the minimum was £300,000.
The large loan Premier team, which was originally 35-strong and based in London, has been reduced to just four London-based staff members who will deal with the pre-application process, while the rest of the case management will be dealt with by the new business team in Edinburgh.
A spokesman for Halifax said the change in staffing was part of its strategy to meet the "changing needs of customers".
It is understood that it involves a net reduction of eight roles.
“As part of our ongoing commitment to the mortgage market, we regularly review and adapt our processes in order to best meet the changing needs of our customers," the spokesman added.