Bertus was admitted as an attorney in 1982 and as conveyancer in 1986. He practised as an attorney and partner in a firm in Richards Bay for 20 years after his admission. He later became the head of the Legal Aid's Office in Pietermaritzburg and occupied this position for 14 years whereafter, he opened his own practice in 2013. He takes a special interest in criminal law, High Court civil litigation and correspondent work.