Personnel is fully proficient for the particular certification level only if it is able to perform all its duties defined by given certification level (as described in the Written Practice) at any given time. However, personnel´s proficiency may change over time (even within one certification period), especially if some tasks are not done on regular basis. Deterioration may be observed in all or only in selected duties. For that reason the NAS 410 / EN 4179 qualification standard requests from the Employer to implement a procedure for annual proficiency review of their NDT personnel, that shall assess the personnel´s ongoing proficiency on regular basis. Unfortunately, the standard does not provide sufficiently detailed list of requirements on its content and therefore the quality of implementation may vary significantly from Employer to Employer. This presentation aims to explain the best practice to implement Annual proficiency Review procedure as was agreed by the Federation of European National Aerospace NDT Boards (ANDTBF) and therefore how is the implementation also recommended for EASA Part 145 (D1) organizations, including motives behind individual requirements. Despite the presentation evolves around aerospace MRO, it shall provide useful information also to OEMs subject to Nadcap accreditation audits or even inspiration how to handle Technical Performance for organizations qualifying their personnel acc. to SNT-TC-1A.