Serial Number
Since ERPNext version 15, the "Allow Negative Stock" option has been deprecated for Serialized and Batch Items. This implies that users can no longer conduct negative stock transactions of serial or batch-tracked items, even if the global Allow Negative Stock flag is set in Stocks Settings. This is an update with enhanced accuracy and control of stock which is in a form of serialization which reduces trackability and error in estimating stock values.
When an item has been marked as a serialized item as described on the Item page, ERPNext actually generates and stores a Serial Number record of the item per individual unit of the item. The Serial Numbers facilitate tracking important lifecycle information such as:
- The location of the serialized item.
- Warranty status (Under Warranty, Out of Warranty).
- End-of-life or expiry date for the particular unit.
- Historic information like which Supplier it was bought from and which Customer it was sold to.
The Serial No status gives immediate visibility into whether a unit is in inventory, delivered, back, or scrapped.
In case of serialized items, ERPNext makes it necessary that you enter the Serial Numbers in the corresponding column while making stock or sales transactions. Insert each Serial Number on a separate line within the multi-line field. This provides detailed traceability and accountability at the unit level.
With this, ERPNext enables the precise tracking and control of individual units of the serialized items.
In order to see the list of Serial Numbers, follow:
1. Prerequisites
Before making and using Serial Numbers then do the following set up:
- Item: Item should be in your Item Master.
- In the Item form, set the checkbox: "Has Serial No".
The setup enables serialization and is mandatory prior to transactions generating or associating Serial Numbers.
2. How to Create a Serial Number
Auto Creation of Serial Numbers
ERPNext automatically generates Serial Numbers while making the following transactions:
- Stock Entry (Material Receipt)
- Purchase Receipt
- Delivery Note
- Sales Invoice
The generation of Serial Numbers is done only if:
- The "Has Serial No" checkbox is marked in the Item.
- There is a naming series specified under the Serial Number setup in the Item master (e.g., "Fridge.#####").
Example: If you get a serialized item via a Stock Entry, ERPNext will automatically generate distinct Serial Numbers such as "Fridge.00001", "Fridge.00002", etc., and associate them with the transaction and warehouse.
Manual Generation of Serial Numbers
There are instances when you might have to create Serial Numbers manually (e.g., legacy stock, imports, or initial configurations). To do so:
Go to the Serial Number list, click New.
Set a unique Serial Number.
Choose the Item Code. Additional information like description, unit of measure, and item group will be retrieved automatically.
Note: If a transaction has previously been effected using that Item, the "Has Serial No" field in the Item cannot be switched.
Click Save.
Note: A manually generated Serial Number does not impact stock levels except if it's associated with a transaction. You cannot set a warehouse on a Serial Number directly except if it is part of a stock transaction such as a Purchase Receipt or Delivery Note.
This protection guarantees that all stock amounts are accurate and traceable through transactional records.
2.1 Notes Regarding Serial Number
In ERPNext (v15+), the status of Serial Number is updated dynamically as per the stock transaction it is related to. This facilitates correct inventory movement tracking and visibility of item-level availability.
- The status of a Serial Number—is automatically marked as, for example, Available, Delivered, Returned, Scrapped, etc.—based on the Stock Entry or Delivery transaction it is a part of.
- Serial Numbers with the status of "Available" only are selectable for outward transactions like Delivery Note or Sales Invoice. This prevents serialized stock from being over-committed or re-used after delivery.
- Serial Numbers are able to be automatically filled in when they are manually entered in the Serial Nos field of a transaction (e.g., Stock Entry or Purchase Receipt). This is useful while importing older stock or when serials need to be manually assigned.
- If you have a Serial Number Series created in the Item Master, you can leave Serial No blank in the Purchase Receipt or Stock Entry. The serial numbers to be created will have the specified format (e.g. ITEM-SR-#####). ERPNext will automatically generate serial numbers using the set format (e.g., "ITEM-SR-#####").
Such flexible serial number generation supports both manual entry and automatic generation, meeting varied operational workflows.
3. Features
When needed to manage the entire life cycle of serialize items, ERPNext also includes mapping and traceability facilities of Serial Numbers to track and trace them:
3.1 Details of Manufacture / Purchase
- Under the Serial No form is the source document, a Purchase Receipt, Stock Entry (Manufacture) or Material Transfer that the Serial Number was created.
- In the event of the purchase of the product, the associated Supplier will be shown. This provides traceability back to the supplier in the event of quality or warranty problems.
- For products which are made, the Work Order or Production Order will be associated, providing traceability into in-house manufacture.
3.2 Delivery Details
- If the Serial Number was sold on a Sales Order or Sales Invoice, the Customer name and related delivery document will be associated.
- With this, you can clearly identify who got which item and when, enabling you to serve the customer quicker, process reverse logistics, and process warranties.
3.3 Warranty / AMC Details
The record concerning the Serial Number can include the following warranty information:
- Warranty Expiry Date
- Expiring AMC (Annual Maintenance Contract)
- The fields can also be employed to query whether the customer is deserving of free service, replacement, or any other after sales support.
- Populate these fields according to the terms on the Sales Order, Delivery Note, or Warranty Claim process.
3.4 More Information
- In the "Serial No Details" section, you can retain custom or additional information pertaining to the individual unit of the item.
Examples are:
Manufacturing or Inspection Notes
- Batch Test Results
- Barcode/QR Code
- Internal Tags or Asset ID references
This section enables companies to individualize serialized tracking in accordance with their quality, service, or compliance needs.