Costco Code CST-MEMO: Unmatched credit memo adjustment.
Costco Unmatched Credit Memo Deductions occur when supplier-issued credit memos cannot be automatically matched against open invoices in Costco's AP system, resulting in manual ledger adjustments.
Why Costco issues Code CST-MEMO.
- Credit memo transmitted without referencing original Costco purchase order or invoice number
- Credit memo amount exceeded open invoice balance
Documents that win.
- Original Credit Memo and Remittance Advice
- Target Invoice and Purchase Order references
- Depot AP correspondence
How to dispute it.
Find remittance line for Code CST-MEMO in Costco Depot Accounts Payable. Note the PO, invoice number, and claim amount.
Collect and verify documentation: Original Credit Memo and Remittance Advice, Target Invoice and Purchase Order references, Depot AP correspondence. Ensure piece counts and timestamps match.
File dispute claim package via Costco Vendor Portal selecting claim reason for Code CST-MEMO (Unmatched credit memo adjustment) 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.