How to Prevent Duplicate Payments in Accounts Payable
Duplicate payments are more common than most businesses realize. Industry research estimates that 0.1% to 0.5% of all accounts payable disbursements are duplicates. For a business paying $1 million in vendor invoices annually, that’s $1,000 to $5,000 walking out the door unnoticed.
How Duplicate Payments Happen
Same invoice, different formats — A vendor emails a PDF invoice, then mails a paper copy. Both get entered separately.
Invoice number variations — INV-001, INV001, and #001 are the same invoice, but manual entry treats them as different.
Multiple approvers — Two people independently process the same invoice because there’s no shared visibility.
Vendor resubmission — The vendor sends a reminder with the invoice attached, and someone processes it as a new invoice.
Credit memo confusion — A credit memo reduces an invoice balance, but the original is paid in full anyway.
Prevention Strategies
1. Centralize Invoice Intake
All invoices should enter through one channel. If invoices arrive by email, connecting your inbox to Foozool ensures each invoice is captured once. The system detects when the same invoice appears in multiple emails.
2. Enforce Invoice Number Matching
Before processing any invoice, check if the invoice number already exists in your accounting system. QuickBooks and Zoho Books will warn you about duplicate invoice numbers — but only if the data is entered consistently.
3. Implement Three-Way Matching
For purchase order-based procurement: match the PO, the receiving report, and the invoice. If any two don’t align, investigate before paying.
4. Set Approval Visibility
Everyone in the approval chain should see the current status of every invoice. When one person approves, others can see it’s handled. Shared dashboards prevent parallel processing of the same document.
5. Audit Regularly
Run a monthly duplicate detection report. Sort by:
- Same vendor + same amount + different invoice numbers
- Same invoice number + different entry dates
- Same amount paid to same vendor within 30 days
Recovery
Found a duplicate payment? Contact the vendor immediately. Most will issue a credit or refund promptly — it’s in their interest to maintain the relationship. Document the duplicate and update your process to prevent recurrence.
The cheapest duplicate payment is the one you prevent. Start with centralizing your invoice intake.