Renewable Energy Assurance Limited operates the Compost Certification Scheme (CCS).

The Compost Certification Scheme is the only independent scheme in the UK aligned and providing a framework for independent assessment and certification of compost to PAS 100, the Compost Quality Protocol, the Scottish Environment Protection Agency's (SEPA's) regulatory position statement, and the CCS Scheme Rules.

Any producer can choose to apply for PAS 100 certification, irrespective of the country/ies in which the compost is used and according to whether it is intended to be supplied as a ‘product' or a ‘waste'.