Negative Stock & Stock Adjustments
This section explains how negative stock transactions create valuation mismatches in ERPNext and why the system generates stock adjustment entries when stock is later corrected through purchase or material receipts.
In many real-world scenarios, businesses enable Allow Negative Stock so that delivery can proceed even when physical stock is not yet available. However, this approach impacts valuation and accounting when subsequent purchase entries are posted with different costs.
1. Scenario Overview
Consider an item “Testing Item Stock Adj” with no available stock in the system. The user attempts to create a Delivery Note, but the system requires a valuation rate since stock does not exist.
To proceed, the user manually enters a valuation rate (for example, 100) so that the Delivery Note can be submitted and stock can be temporarily issued.
When stock is not available, ERPNext uses the manually provided valuation rate to temporarily book stock and update Stock-in-Hand values.
2. Delivery Note Impact
After submission of the Delivery Note, ERPNext creates stock ledger and accounting entries based on the valuation rate of 100. Since no actual stock existed, the system records a negative stock position.
This results in a temporary valuation mismatch because the system assumes the cost of goods sold (COGS) at the provisional rate entered during the Delivery Note.
3. Purchase Receipt After Delivery
Later, the user creates a Purchase Receipt for the same item with an actual purchase cost of 300. However, this entry is posted after the Delivery Note date.
At this stage, ERPNext faces a valuation conflict because earlier stock movements were already recorded using a different cost basis (100 vs 300).
ERPNext uses the last available valuation rate (from the earlier transaction) to maintain consistency in stock valuation. If it directly used 300, stock value and quantity would not reconcile correctly.
4. Stock Adjustment Entry
Because of the difference between the Delivery Note rate (100) and Purchase Receipt rate (300), ERPNext generates a stock adjustment entry.
This adjustment ensures that the financial impact is correctly reflected in the books by posting the difference (200) into the Stock Adjustment / COGS account.
This keeps stock quantity correct while ensuring accounting remains balanced.
5. How to Avoid This Issue
- Avoid using Allow Negative Stock in valuation-sensitive environments.
- Ensure purchase entries are posted before delivery transactions (backdated correctly).
- Maintain proper FIFO/Moving Average flow so valuation rates remain consistent.
When purchase entries are backdated correctly, ERPNext automatically recalculates stock valuation and eliminates the need for adjustment entries.
6. Result After Reposting
Once a backdated Purchase Receipt is submitted, ERPNext triggers a reposting process that recalculates stock valuation across all affected transactions.
After reposting:
- Delivery Note valuation is updated from 100 to 300
- Stock-in-hand reflects correct valuation
- No additional adjustment entries are required
7. Key Takeaway
Negative stock allows operational flexibility but creates valuation complexity. ERPNext resolves this through stock adjustment entries and reposting logic to ensure financial accuracy across inventory transactions.
