He will be joining Newcastle Building Society in September as head of intermediary mortgages.
Truswell joined Together in July 2017 after a short period at Capital Home Loans.
Together commercial CEO Marc Goldberg thanked Truswell and praised him for his part in the lender’s significant growth over the last two years.
“We can confirm that our head of national accounts, John Truswell, will be leaving the group,” said Goldberg.
“In the two years John has been with Together, he has been instrumental in forging intermediary relations across the group, most notably through new partnerships with some of the UK’s leading networks and clubs.
“We would like thank him for the contribution he has made to building Together’s success and we all wish him well for the future.”
Newcastle Building Society customer director Stuart Miller welcomed Truswell’s appointment.
“We’re really pleased that John will be joining the team in September as our new head of intermediary mortgages,” he said.
“He will be a great addition to the society in helping us continue to build strong relationships with our intermediary partners and further increase our presence and impact in the mortgage market.”