Segment reporting
The breakdown of a conglomerate into its parts. It is where you find out that the exciting division is small and the boring one pays for everything.
A consolidated income statement adds every division together into one revenue figure and one profit figure. For a company doing two unrelated things, that total describes neither of them.
What must be disclosed
Accounting standards require companies to report separately on their significant operating segments, giving at minimum revenue and a measure of profit for each, plus reconciliation to the group totals.
Both IFRS and US standards use the management approach: a segment is a component whose results the chief operating decision maker reviews separately. That is a defensible rule with an obvious consequence — a company that internally manages two very different businesses as one unit may legitimately report them as one segment, and the detail is simply unavailable.
What it reveals
- Where the profit actually is. A division can be a third of revenue and nearly all of operating profit. The group margin conceals this completely.
- Cross-subsidy. A loss-making growth business funded by a mature cash generator is a strategic choice, and one you can only evaluate if you can see both halves.
- Which growth is real. A 10% group growth rate could be 40% in a small division and 2% elsewhere, or 10% everywhere. Those are different companies with the same headline.
- Geographic exposure. Revenue by region shows currency and political risk that the consolidated figures blend away. See currencies and exchange rates.
The limits
Segment profit is usually operating profit before central costs, and the allocation of shared expenses — head office, research, brand marketing — involves real judgement. Two companies can allocate the same costs quite differently and both be within the rules.
When a company reorganises its reporting segments, previously visible detail sometimes disappears — a struggling division is merged into a healthy one, and the trend becomes untraceable. Companies are required to restate prior periods on the new basis, which helps, but a segment that stops being disclosed separately is a question worth asking at the next results call.
How to use it
Build a five-year table of revenue and operating profit by segment, and calculate each segment's margin and its share of group profit. Ten minutes of work, once a year, and it usually changes how you describe the company.
It also feeds valuation directly: a sum-of-the-parts approach values each segment against relevant peers rather than applying one multiple to a mixture. See valuation methods.