Tail spend is the portion of procurement volume spread across a very large number of suppliers, each with small individual value.
Structure. A Pareto pattern: a small share of suppliers accounts for most of the volume.
Why it stays unmanaged. Process cost per event is largely volume-independent and exceeds the achievable saving for small requirements.
Risks. Poor spend visibility, an uncontrolled supplier base, duplicate engagement.
Approaches. Bundling, master agreements with call-off rights, standardisation, automation.