“Major organizational change turns small control gaps into costly leaks. AP is where they surface first.” — Ashley King
Mergers, divestitures, and ERP cutovers create pressure and extra work for Accounts Payable. During times of organizational disruption, the risk for errors rises because people are juggling new roles, learning new systems, and dealing with uncertainty, while processes run in parallel, and vendor data is in flux. The practical question is not whether risk increases, but where it shows up and how to contain it.
Prometheus Group states, “When you are about to merge two companies with the same type of Enterprise Resource Planning (ERP) system together, you probably do not anticipate running into many issues. However, that could not be farther from the truth.”
Why payment errors spike during M&As
When organizations merge, employee uncertainty often creeps into daily operations, and that uncertainty breeds manual mistakes. Teams adjusting to new leadership, shifting processes, and competing priorities can easily overlook small details that lead to costly errors. Add the chaos of running two (or more) ERP systems in parallel, and it’s easy to see how the same invoice can be approved and paid twice.
Running parallel systems also tends to create duplicate vendor files, compounding the problem. On top of that, merging two or more vendor master files often results in a slew of inconsistent or redundant vendor records, which is one of the most common sources of duplicate payments. Together, these conditions create a perfect storm for payment errors to surge.
Supplier confusion adds another layer of complexity. Vendors may invoice both the legacy and new entities, or continue using outdated remit-to details, increasing the chance of duplicate billing. Compounding the issue, controls don’t automatically transfer during migrations. As Deloitte notes, when organizations move to new cloud or ERP environments without fully replicating or testing existing controls, operational and reconciliation risks can persist well after go-live.
What an AP Recovery Audit typically uncovers after a merger or acquisition
- Duplicate payments. Paid from two systems during parallel run, or twice in one system due to duplicate vendor IDs.
- Vendor master duplicates. Slight differences in name, address, tax ID, or banking information can create multiple records for one supplier.
- Unapplied credit memos. Credits can get missed during cutovers or sit on a legacy entity’s ERP or system and never get applied.
- Contract or PO term mismatches. Incorrect prices or terms can populate catalogs and POs as data is remapped across systems.
- Wrong remit-to or banking updates. Payments flow to old accounts when vendor updates lag consolidation
Practical moves that reduce leakage
- Assign clear ownership for data and process changes. Designate a single leader responsible for enforcing standards before, during, and after system consolidation. This avoids inconsistent setups and prevents uncontrolled workarounds.
- Run a comprehensive vendor master cleanup and deduplication — such as VendorVALIDATE, before migration. This should include TIN, bank, address, and fuzzy name matching to eliminate fragmentation and reduce the risk of duplicate suppliers being created in the new environment.
- Perform an AP recovery audit on both systems during a parallel run. If parallel systems are unavoidable, use cross-system duplicate detection combined with a one-payment gate to prevent the same invoice from being processed twice across legacy and new platforms.
- Strengthen supplier communication. Provide clear billing and remit-to instructions and monitor invoices referencing legacy entities or outdated information. This reduces misdirected invoices and downstream duplicates.
- Conduct a post-cutover quality assurance review three to six months after go-live. Once transaction and statement volumes stabilize, run a targeted AP recovery audit or quality-control review to surface remaining duplicates, unapplied credits, and incorrect postings, before they become entrenched.
- Augment native ERP controls. Supplement standard ERP rules with duplicate prevention and anomaly-detection logic capable of catching near-matches, line-level duplicates, and subtle errors. Periodic AP recovery audits can further identify control gaps and provide actionable recommendations to strengthen your environment, long term.
Bottom line
In periods of major change, an AP Recovery Audit does two jobs at once. It helps recover dollars that leaked during people, process, and system transitions, and pinpoints control gaps so you can tighten processes for the next close.
Sources
- McKinsey & Company, “Leading through uncertainty: Navigating delays in M&A deals”, Feb 29, 2024.
- Harvard Business Review, “How to Get Results Quickly After a Merger or Acquisition”, Jun 14, 2024.
- Deloitte, “How AI-powered ERP controls transform TMT”, Sep 30, 2025.
- Prometheus Group “How to Merge Two ERP Systems After a Business Acquisition” Oct 20, 2022
