Rosser is a retired chartered accountant living in Waikato. He applied accounting while working for 45 years in a diverse range of organisations, both private and public. Since moving from Auckland in 2014 he has provided back-office support at Hamilton Budgeting Advisory Trust. Rosser joined the FinCap Board in 2018 and is currently treasurer. After moving to Raglan he and his wife Lesley joined St Peters Anglican church where Rosser helps with the music programme and serves on the vestry.

He is a Trustee to provide a perspective for service providers operating in the North Island (south of Auckland to Wellington).