[en] Inspections of nuclear facilities by the International Atomic Energy Agency to verify compliance with the terms of the Nuclear Nonproliferation Treaty combine both materials accounting (MA) and containment/surveillance (C/S) methods. Interfaces between these two safeguards measures are necessary to assure that the operators's and inspector's measurements of material are accurate and complete. This report describes those interfaces where C/S can provide the necessary protection for measurement instruments and information used in MA. General considerations that influenc the MA and C/S interface are described. The report also includes specific examples of interactions between MA and C/S in a light-water reactor and in a reprocessing facility