The National Social Security and Insurance Trust (NASSIT) was established through an Act of Parliament and is charged with the responsibility of administering the Sierra Leone Pension Scheme. NASSIT started full operations in January 2002 as a defined benefits pay-as-you-go pension system. Membership is compulsory for all workers in the public and private sector and optional for self-employed persons and workers in the informal sector. It is incumbent on all employers to ensure that their workers are registered and contributions paid on their behalf not later than the 15th day after the month for which contributions are due. This condition is clearly stipulated in Section 31 of the NASSIT Act No. 5 of 2001, which is the governing legislation for the scheme.

However, like many social security institutions in Sub-Saharan Africa, a fundamental administrative challenge NASSIT faces relates to social security contribution collection and the enforcement of compliance. The scheme was forced to explore several strategies beginning from 2015 to positively influence the behaviour of employers and employees to increase their compliance and reduce the incidence of contribution evasion.