Master data governance and access controls create the most significant downstream issues for SMEs, as weak customer, vendor, or item data—and conflicting user access rights—can undermine core cycles such as Order‑to‑Cash and Procure‑to‑Pay. While O2C or P2P reviews may deliver rapid operational improvements, recurring problems in cash, procurement, inventory, and reporting often stem from poor data discipline and insufficient access oversight. Pairing any main process review with a light master‑data and access scan therefore ensures sustainable improvements and prevents system‑level gaps. This article provides practical guidance to help SMEs prioritize controls and strengthen long‑term operational reliability.