Nicholas accepts briefs in all areas of practice but has specialist experience and expertise in administrative, commercial, regulatory and taxation law.

He does advocacy and advisory work for individuals, companies, Government departments and regulatory agencies. He regularly appears in most courts, especially the Federal Court, State courts (all levels), the Federal Circuit Court and the Administrative Appeals Tribunal.

Prior to coming to the Bar, Nicholas practised as a solicitor at Clayton Utz and later at Sparke Helmore. That work primarily involved administrative and commercial law litigation and advising.

Nicholas also served as Tipstaff to Justice Bergin, Chief Judge in Equity, Supreme Court of New South Wales. He has taught and acted as an examiner in constitutional law, administrative law and statutory interpretation courses at the Australian National University.