Costco Code CST-AUD: Post-audit claim deduction (third-party audit).
Costco Post-Audit Claim Deductions are generated by third-party auditors reviewing historical Costco invoices, allowances, and purchase orders for over-billings or missed deductions. Every claim requires line-by-line verification against historical records.
Why Costco issues Code CST-AUD.
- Post-auditors retroactively applied promotional allowances to non-promotional POs
- Historical unit price or pack-size discrepancy claimed
- Duplicate payment or missed trade allowance claimed
Documents that win.
- Complete post-audit claim package
- Original signed Costco Vendor Agreements and promotional deal sheets from the audited period
- Original POs, Invoices, and remittance proof
How to dispute it.
Find remittance line for Code CST-AUD in Costco Depot AP & Post-Audit Team. Note the PO, invoice number, and claim amount.
Collect and verify documentation: Complete post-audit claim package, Original signed Costco Vendor Agreements and promotional deal sheets from the audited period, Original POs, Invoices, and remittance proof. Ensure piece counts and timestamps match.
File dispute claim package via Costco Vendor Portal selecting claim reason for Code CST-AUD (Post-audit claim deduction (third-party audit)) and attaching all verification documents.
Monitor claim status in Costco Vendor Portal until approved (30-45 days). Approved credit memo will apply to a future settlement remittance.
Dispute within 6 to 12 months of deduction issuance. Check your remaining filing window with our free Dispute deadline checker.
Source: Costco supplier guidance · Verified by Laxmi Narayan · 2026We audit remittances, assemble proof documents, and handle end-to-end Costco deduction recovery on pure contingency. We'll check whether yours is disputable, free, in 72 hours.