A state of consistency that exists across financial statements of an entity across different accounting periods. This relates to application of consistent accounting policies, procedures, treatments, and methods, period to period. For example, the amounts and values reported in the statement of financial position (SFP) and the statement of income (P&L) for a given accounting period must be calculated and estimated in line with those of earlier periods.

Horizontal consistency allows an entity to have a better comparative perspective in relation to its year-to-year performance (e.g., current and next accounting periods).

In addition to vertical consistency, consistency comes in other forms, which are: vertical consistency and third dimensional consistency.