There are 11 different classes of PRSI, which fall broadly under the following 5 headings:
employees in the private sector and certain public servants (Classes A, E and J)
certain public servants (Classes B, C, D and H)
self-employed people, this includes certain company directors and members of a local authority (Class S). Class S and P applies to certain self-employed share-fishermen.
people with no PRSI contribution liability (Class M)
certain Public Office Holders (Class K).
The following is a brief description of the people covered by each of the main PRSI contribution classes.
Employees in industrial, commercial, and service-type employment, who are employed under a contract of service with reckonable pay of €38 or more a week from all employments; civil and public servants recruited from 6 April 1995 and Community Employment workers from 6 April 1996. Most workers in Ireland pay Class A PRSI contributions.
certain public office holders with an income in excess of €100 per week. The public office holders affected include the President, members of the Oireachtas, the judiciary, certain military judges, the Attorney General, the Comptroller and Auditor General and certain members of the European Parliament). These Public Office holders are liable for PRSI at a rate of 4% on that income.
any of these specified public office holders who earn €5,200 a year or less (€100 a week or less) have a nil liability – see Class M.
Class K also applies to the additional earned self-employed income from a trade or profession of a modified rate contributor and on any unearned income they have
Employed contributors and occupational pensioners aged under 66 years whose only additional income is unearned may be liable for PRSI contributions on this income.