Joint interest billing (JIB) is how an operator bills the other working interest owners of a well or facility for their shares. A working interest must pay its proportion of eligible exploration and operating costs. When several owners have this obligation, the operator records the costs in a joint account and uses JIB to recover the partners' shares. JIB concerns the cost side, not the distribution of proceeds from production.
The ownership deck (also known as a Division of Interest or DOI deck) contains the individual owners' interests in the property. Each ownership entry has an effective date indicating when that interest begins. When an interest changes hands during a billing period, the operator uses the relevant ownership shares for costs incurred on either side of the change.
The Joint Operating Agreement (JOA) governs the relationship of the owners and the operator's authority to charge shared costs. A JOA may include a COPAS accounting procedure as an exhibit. That procedure contains the rules for chargeable costs and overhead recovery under the agreement. The operator must check charges against the JOA and relevant accounting procedure and cannot assume all joint accounts follow the same rules.