In the first 90 days, this role moves through three phases: establishing control (documenting end-to-end billing flows, baselining accuracy and cycle time, standing up an exception queue and an interim Finance-CX RACI); stabilizing operations (launching pre-release review for high-risk billing files, implementing a check/payment reconciliation log, and running Quote-to-Cash UAT against real failure scenarios); and reducing recurrence (closing out priority root causes, publishing a scorecard, and formalizing SOPs and escalation thresholds). By six months, you're equally comfortable auditing a high-risk billing file as you are chasing down an unmatched check, building a RACI, or walking a customer-facing partner through exactly where an issue stands, why it happened and when it'll be resolved.