Segment Reporting

Companies report results by operating segment, defined as the components whose results the chief operating decision maker reviews. RevenueRevenueWhat a company billed customers over the period, before any cost is subtracted.Read the full explanation, a measure of profit, and assets are disclosed for each, together with geographic breakdowns and any customer above ten percent of revenue.

The rule ties segments to internal management rather than to any external taxonomy, which is why segments differ so much between superficially similar companies. It also means the segments tell a reader how management thinks about its own business.

A company reporting three percent revenue growth might have one segment growing forty percent and another shrinking fifteen. The consolidated number describes neither, and the trajectory of the business depends entirely on which is which.

The arithmetic makes the difference stark over time. A business that is forty percent of revenue growing at forty percent, alongside sixty percent shrinking at fifteen, looks flat this year and is a completely different company in three.

Segment profit is disclosed alongside segment revenue, so segment margins can be computed directly. They usually differ far more widely than the consolidated figure suggests.

That spread has a direct valuation consequence: a company whose growth is concentrated in its lowest-margin segment will see consolidated margins fall as it grows, and the consolidated figure alone makes that look like deterioration rather than mix.

Segments change when a company reorganises, and prior periods are restated so the comparison stays valid. The change is disclosed, and it is worth reading.

A segment that was reported separately and is now folded into a larger one becomes considerably harder to track from the outside. That is sometimes an honest reflection of how the business is now run and sometimes it removes visibility of something that was deteriorating, and the filing does not say which.

Segments are not defined by the accounting standards as product lines or geographies. Under the management approach, a reportable segment is a component whose results the chief operating decision maker regularly reviews when allocating resources. The disclosure is therefore a window into how the company is actually run.

That has a consequence worth drawing out: a company that reports one segment is asserting that its management does not review the parts separately. For a genuinely single-product business that is accurate. For a diversified one it is a choice, and it removes the reader's ability to see anything underneath.

The thresholds are mechanical: a component is reportable if it accounts for at least ten percent of revenue, of profit, or of assets, and reported segments must together cover at least seventy-five percent of external revenue. Everything else is aggregated into an other line, which is where a struggling business can sit for years without being visible.

The standard requires a specific and limited set of measures per segment, and reading the disclosure well starts with knowing which questions it can and cannot answer.

The second row is the important limitation. Segment profit is defined by management, may exclude corporate overhead entirely, and does not have to reconcile to any GAAPGAAPThe standardised US accounting rules a filed statement must follow.Read the full explanation subtotal except in aggregate. A segment margin is therefore comparable across periods for one company and rarely comparable between two.