Single Source of Truth Definition
A Single Source of Truth (SSOT) is a state in which everyone in an organization refers to the same authoritative version of a given piece of data, no matter which system or team they work in. Rather than maintaining the same information in several places that gradually drift apart, an SSOT establishes one definitive source that all others reference, so there is never any question about which value is correct.
How is a single source of truth achieved?
A single source of truth is a goal reached through practice, not a single tool you install. It usually depends on consolidating data from scattered systems, resolving duplicates and conflicts into one trusted record, and then designating that record as authoritative so downstream systems consume it instead of keeping their own copies. This is exactly what Master Data Management sets out to do for core entities such as products, suppliers, and customers. A closely related idea is the System of Record, which names the specific system deemed authoritative for a particular type of data.
Why does it matter?
When the same fact lives in multiple places, those copies inevitably diverge, and teams end up arguing over whose numbers are right instead of making decisions. Inconsistent data undermines reporting, automation, and customer experience alike. A single source of truth removes that ambiguity: a value updated once is correct everywhere, giving every team and every system a consistent basis to work from and making the data genuinely trustworthy.
