An accounting report provided by the State to the IAEA "showing the material balance based on a physical inventory of nuclear material actually present in the material balance area. The reports shall be dispatched as soon as possible and in any event within 30 days after the physical inventory has been taken…"the material balance reports shall include the following entries, unless otherwise agreed by the Agency and the State:

• Beginning physical inventory
• Inventory changes (first increases, then decreases)
• Ending book inventory
• Shipper/receiver differences
• Adjusted ending book inventory
• Ending physical inventory; and
• Material unaccounted for."

(INFCIRC 153*)

An MBR must be submitted even where there was no nuclear material in the material balance area at the time of the physical inventory taking and where no inventory changes occurred during the relevant material balance period, as long as the material balance area continues to be subject to IAEA safeguards.