Joint cost
Joint cost is the shared cost of a process producing joint outputs before the split-off point. It can be apportioned using physical measures or relative values for reporting purposes, depending on the required method. Once incurred and unchanged between alternatives, it is irrelevant to a further-processing decision. The fact that a product shows a loss after an arbitrary joint-cost allocation does not prove that discontinuing or processing it differently will improve total profit.
Worked example
A process costs $20,000 before A and B separate. Refining A adds $3,000 and raises its sales value by $5,000, so further processing improves profit by $2,000 regardless of the existing joint-cost allocation.
Common mistake
Do not use an allocated historical joint cost to reject incremental profit from further processing.
Where it appears in your exams
| Qualification | Exam | Relationship | Period |
|---|---|---|---|
| ACCA | MA | Direct | September 2026–June 2027 |
| ACCA | PM | Direct | September 2026–June 2027 |
| FIA | FMA | Direct | September 2026–June 2027 |
