Under the Safety Case Regulations, the duty holder must appoint an Independent Competent Person (ICP) to verify that safety critical elements are suitable and remain suitable for the life of the installation. The ICP must have the sufficient skills and knowledge to carry out this function, and must be free from any external pressures (e.g. financial, production or management) which could affect their objectivity when carrying out verification activities. This term is often interchanged with 'verifier' or 'IVB' (Independent Verification Body).
In simple terms: A person appointed by the duty holder to verify that safety critical elements on an installation are, and remain, suitable.