Item Serial Number
Go to: Inventory → Items → Item Serial Numbers
A serial number identifies one physical unit. Where a batch says “these 500 pieces came from the same run”, a serial says “this exact machine, with this exact history”.
Serial numbers only apply to items where Has Serial Number is switched on.
When to use serial numbers
| Use serials when… | Use batches instead when… |
|---|---|
| Each unit is high value (machines, vehicles, instruments) | Units are only distinguishable by production run |
| Each unit carries a warranty tied to that unit | Warranty is by lot or not tracked |
| Regulation requires unit-level traceability | Lot-level traceability is enough |
| You must know exactly which unit a customer received | Knowing the lot is sufficient |
An item cannot have both Has Batch Number and Has Serial Number. Batch FIFO allocation and per-unit serial allocation are incompatible ways of picking physical stock.
Serial number fields
| Field | What it means |
|---|---|
| Serial Number | The identifier itself (the serial record’s document number) |
| Item | The serial-tracked item |
| Warehouse | Where this unit currently is |
| Status | Draft / In Stock / Active / Delivered / Cancelled |
| Purchase Rate | What this unit cost on receipt |
| Manufacturing Date | When the unit was made |
| Expiry Date | When the unit expires, if applicable |
| Purchase Document | The GRN or receipt that brought it in |
| Delivery Date | When the unit left |
| Delivery Document | The Delivery Note or issue that took it out |
| Description | Free-text notes for this unit |
Serial number lifecycle
| Status | Meaning |
|---|---|
| Draft | Created but not yet attached to an approved movement |
| In Stock | Assigned to a draft inward document, waiting for approval |
| Active | Approved and physically available in the warehouse |
| Delivered | Issued out to a customer or consumed |
| Cancelled | Voided — no longer part of stock |
Only Active serials can be issued out. A serial sitting in In Stock belongs to a draft receipt that has not been approved yet.
How serial numbers get created
Serials are normally created during a receipt, not typed in advance:
| Source | How serials arrive |
|---|---|
| Goods Received Note | Enter the serial numbers on the item row — one per received unit |
| Stock Entry (Receipt) | Same, on the inward row |
| Manufacturing Entry | Serials are assigned to finished units produced |
| Stock Opening | Opening units can be brought in with their existing serials |
| Item Serial Numbers screen | Create records manually, then select them on the receipt |
Serial Number Prefix
Set Serial Number Prefix on the item master to control how generated serials are named — for example prefix PUMP-A producing PUMP-A-0001, PUMP-A-0002. Keeping prefixes per product family makes scanning and searching much easier.
Using serials on transactions
On receipt
Every unit received must have a serial. If you receive 10 units, you supply 10 serial numbers. ERPX rejects the document if the count of serials does not match the received quantity.
On issue or delivery
Pick the exact serials leaving the warehouse. The Delivery Note, Stock Entry (Issue), or Transfer records which unit went where, and the serial’s status moves to Delivered on approval.
On transfer
The serial’s Warehouse is updated to the destination — the unit’s identity stays the same, only its location changes.
Approving an outward document without selecting serials for a serial-tracked item is blocked — you will see a “Serial Numbers Required!” message. Select the units before approving.
Tracing a unit
| Report | Answers |
|---|---|
| Serial Wise Item Ledger | Full movement history of one serial number |
| Transaction Chain | Every linked document from purchase through to sale |
Between them you can answer: which PO bought this unit, which GRN received it, what it cost, which warehouse held it, which Delivery Note sent it out, and to which customer.
Tips
- Use the manufacturer’s own serial where one exists — it is what appears on the physical unit and on warranty claims.
- Scan rather than type. Serial entry is where receipt errors happen most.
- Do not enable serial tracking on fast-moving low-value stock. The data-entry cost is real and the benefit is small.
- Record Purchase Rate — it is what makes per-unit margin analysis possible later.