The band split with previous management , Mucho Bravado, late last year.
The deal is believed to be a co-manage arrangement, with Cullen focusing on Australia and Bryan looking at international opportunities.
The band are familiar with the Stop Start as they are signed a label deal with the company last year. They are also booked by Select, whose head Stephen Wade is a co-founder of Stop Start.
Their album Museum was released last October, was triple j's Album Of The Week and debuted at nine on the ARIA Album Chart.