Fellowship of the Institute of Physics (FInstP) is "the highest level of membership attainable" by physicists who are members of the Institute of Physics (IoP), "for those with a degree in physics or related subject (or equivalent knowledge gained in the workplace) and who have made a significant impact on their sector"; it is for "distinguished physicists in recognition of their accomplishments".
The Institute of Physics (IOP) is a UK-based not-for-profit learned society and professional body that works to advance physics education, research and application. It was founded in 1874 and has a worldwide membership of over 20,000. The IOP is the Physical Society for the UK and Ireland and supports physics in education, research and industry. In addition to this, the IOP provides services to its members including careers advice and professional development and grants the professional qualification of Chartered Physicist (CPhys), as well as Chartered Engineer (CEng) as a nominated body of the Engineering Council; it also holds its own separate Royal Charter. The IOP's publishing company, IOP Publishing, publishes 85 academic titles.