Part 2: If you find yourself trying to find the problem in a bad Parts Inventory Reconciliation and have exhausted all common methods to find the error, here are other places to look;

Aftermarket parts value postings vs Parts value posting in DMS
Bulk Oil Adjustments (sell a full liter, but give customer a decimal liter)
Discounts Earned Postings – and how these are handled in both parts dept DMS and accounting
Freight Postings – it’s an expense, not parts inventory
Credits Posting – how both Parts and Accounting handle credits
Shop Tools Postings (when missing dollars in parts vs accounting)
Parts Returned (OEM and/or Aftermarket) – credit not received or posted
Credit Card or Prepaid Purchases
Inventory Appreciation/Depreciation – should be recorded monthly