SAP Knowledge Base Article - Public

3755199 - Moving average price for material would be negative- Message no. M8783

Symptom

While posting a supplier invoice, the system blocks the transaction with error “Moving average price for material would be negative” (Message no. M8 783).

Environment

SAP S/4HANA Cloud Public Edition

Reproducing the Issue

  1. Create Purchase Order (PO)

    • Use Manage Purchase Orders app or ME21N 
    • Maintain and note the material price

  2. Post Goods Receipt (GR)

    • Use Post Goods Movement app or MIGO
    • Post GR against the PO (stock updated with PO price)

  3. Reduce Moving Average Price (MAP)

    • Use Change Material Price app
    • Lower MAP (e.g., via manual change, exchange rate, or price update, reason could be anyting, Price change in Exchange rate or Price changed in MR21 or PIR updated with new price) 

  4. Post Supplier Invoice

    • Use Create Supplier Invoice (F0859) app or MIRO
    • Enter PO reference and simulate/post invoice

  5. Observe Error

    • System triggers error: M8783
    • “Moving average price for material would be negative”

Cause

  • There is a significant difference between the Goods Receipt (GR) price and the Invoice price.
  • The invoice price is lower than the GR price, while the material is valuated at moving average price.
  • During invoice posting, the system recalculates the Moving Average Price (MAP).
  • Due to the price difference, the new calculated MAP becomes negative, triggering the error M8783.

Resolution

  1. Check Material Stock & Value

    • Open Display Material (F1602) app
    • Navigate to the Accounting View
    • Note:
      • Total stock quantity
      • Current inventory value

  2. Verify Goods Receipt (GR) Value

    • Open Display Material Document app or MIGO 
    • Locate the relevant GR document
    • Review:
      • Quantity posted
      • Total GR value

  3. Verify Invoice Value

    • Open Create Supplier Invoice (F0859) app or Supplier invoice -advance  (MIRO)
    • Simulate the invoice posting
    • Note:
      • Invoice amount (credit/debit difference causing the issue)

  4. Calculate New Stock Value

    • Use the formula: 
      New Stock Value = Current Inventory Value + Invoice Value – GR Value
    • Check if the result is negative (expected)

  5. Calculate New Moving Average Price (MAP)

    • Use the formula: 
      New MAP = New Stock Value / Total Stock Quantity

  6. Update Material Price

    • Open Change Material Price app
    • Enter material and valuation area
    • Update the Moving Average Price (MAP) - from step 5.
    • Apply a slight buffer (higher value) to avoid recurrence
       
  7. Post Invoice again and error will not come. 

  8. Update MAP back to it original value to avoid wrong inventory valuation.  

See Also

Keywords

miro, invoice verification, moving average price negative, M8783, map negative, posting blocked, exchange rate change, manage material valuations, mr22, salk3, goods receipt, gr/ir, price difference, stock value adjustment, currency rate , KBA , MM-FIO-IV-2CL , Fiori UI for Invoice Verification (Public Cloud) , Problem

Product

SAP S/4HANA Cloud Public Edition all versions