Serial Number Management
Allow Negative Stock has been removed for Serial / Batch items from Version 15. Even if “Allow Negative Stock” is enabled in Stock Settings, negative stock transactions are not allowed for serialized items.
Serial Number (Serial No) tracking in ERPNext is used to uniquely identify each individual unit of a serialized Item. Every single quantity gets its own Serial Number, allowing precise tracking across the entire inventory lifecycle.
This helps organizations track warranty, ownership, movement history, supplier source, and customer delivery for each unit separately.
1. Prerequisites
Before using Serial Number tracking, ensure the following setup is completed:
- Create an Item in the system (Item master is required first).
- Enable Has Serial No in the Item master for serialized inventory tracking.
- Enable Serial and Batch feature from Stock Settings (if not already enabled).
Configuration Requirement
Serial Number tracking works only when the Item is marked as “Has Serial No”. Without this, serial tracking will not be available in stock transactions.
2. How Serial Numbers are Created
Serial Numbers are typically created automatically during stock transactions involving serialized items.
- Enable Has Serial No in the Item master.
- Define a Serial No Series (example format: PB2L.#####).
- Submit a stock transaction such as Purchase Receipt or Stock Entry.
- The system automatically generates Serial Numbers based on the defined series.
System Behavior
If a Serial Number series is configured, ERPNext automatically generates Serial Nos during stock entry submission, eliminating the need for manual entry.
2.1 Manual Serial Number Creation
In some cases, Serial Numbers can be created manually:
- Go to the Serial Number list and click New.
- Enter a unique Serial Number.
- Select the related Item (Item must already exist).
- Save the record.
Once a Serial Number is used in any stock transaction, it cannot be modified or reassigned.
3. Key Features
3.1 Lifecycle Tracking
Each Serial Number maintains a complete history across transactions:
- Purchase source (Supplier details)
- Sales destination (Customer details)
- Movement across warehouses
Traceability Benefit
Serial tracking enables full traceability of each unit from procurement to final sale, including service and warranty history.
3.2 Warranty and AMC Tracking
Serial Numbers can store service-related information:
- Warranty start and expiry dates
- AMC (Annual Maintenance Contract) coverage
- Service lifecycle details per unit
3.3 Inventory Status
Each Serial Number has a status that reflects its current state in inventory:
- Available: Ready for sale or transfer
- Delivered: Already sold or issued
- Returned: Returned from customer
4. Using Serial Numbers in Transactions
Serial Numbers must be selected or assigned in all stock transactions involving serialized items:
- Purchase Receipt
- Stock Entry
- Delivery Note
- Sales Invoice (if inventory-enabled)
Each unit must have a valid Serial Number assigned before submission.
Important Rule (Version 15)
Negative stock transactions are not allowed for Serial Number items, ensuring strict inventory accuracy and preventing inconsistencies.
5. Key Considerations
- Each unit is uniquely tracked using a Serial Number.
- Serial Numbers cannot be reused once transacted.
- Stock valuation and movement are tracked at unit level.
- Warranty and ownership history is permanently recorded.
6. Related Topics
- Item Codification
- Item Variants
- Serial Number Naming
- Stock Entry
- Batch Management
