The South African Sanitation Technology Evaluation Programme (SASTEP), run by the Water Research Commission (WRC), is designed to foster a local sanitation industry to increase access to safe and dignified sanitation.  The WRC requires the field-testing and demonstration of sanitation prototypes so that they can be assessed against a range of performance criteria.  The guidelines aim to provide SASTEP grantees with a clear understanding of the requirements of rigorous field‑testing, based on the experience gained from the Engineering Field Testing Platform, with additional guidance for supporting laboratory and municipal or regulatory partners.  During the development process, two workshops were held with technology developers, regulators and commercial partners in Durban (November 2019) and in Pretoria (March 2020).