An instrument for cooperation between two or more national institutions, eventually also involving cooperation with relevant stakeholders such as social partners to undertake activities defined either in law or policy to tackle undeclared work. National agreements can have many different forms such as legal prescriptions, memorandum of understanding, strategic documents and action plans, and executive orders.

Sometimes referred to as a ‘black list’, this is a list of businesses or individuals who have been non-compliant and therefore are regarded as unacceptable or untrustworthy, and often marked down for punishment (e.g., negative publicity) or exclusion (e.g., from tendering for public procurement contracts).