When figures disagree across CRMs, ERPs, and data platforms, reconciliation restores trust. Define your control total records, quantities, and monetary amounts—first, then build automated matching that supports one-to-one, one-to-many, and many-to-many relationships. Apply configurable tolerances for timing differences, currency rounding, and late-arriving adjustments. Design rules are implemented in tiers: deterministic keys (IDs), fuzzy heuristics (such as names, dates, and amounts), and finally, human review for edge cases. Surface exceptions in a queue with owners, SLAs, and audit trails; capture root causes so fixes become permanent. Dashboards should display coverage, category breaks, and aging, while daily attestations document the completeness and accuracy of the data. With clear metrics and repeatable workflows, reconciliations move from painful month-end marathons to calm, continuous controls through automation.