Sarah Havlin is a solicitor by background and has acted in several judicial and quasi-judicial  roles, including as the Certification Officer of Northern Ireland, a quasi-judicial and statutory regulation role in trade union affairs.

She has played a significant role in the review of local government boundaries in Northern Ireland since 2008 and is currently the Local Government Boundaries Commissioner of Northern Ireland. She has previously served as Assistant District Electoral Areas Commissioner and as an independent Ministerial advisor on the revised terms and conditions for local government representatives.

Sarah was reappointed to the Boundary Commission for Northern Ireland by the Secretary of State in December 2020.