ERPNext inventory management is a fully integrated stock module that tracks every item across multiple warehouses, values it automatically using FIFO or moving average, and keeps your stock ledger and accounting books in perfect agreement. It handles batch and serial traceability, automatic reordering, and a full set of stock reports out of the box.
Short answer
ERPNext inventory management is the built-in Stock module that records every inward and outward movement, values stock via FIFO or moving average, and syncs quantities with your accounts in real time. It supports tree-structured warehouses, batch and serial tracking, reorder-driven material requests, and reports like Stock Balance, Stock Ledger, and Stock Ageing. ERPNext itself is free and open source under GPLv3.
I am Manoj, an ERPNext implementation consultant at Mith Tech in Bengaluru. Most inventory problems I get called in to fix are not software bugs — they are setup decisions made without understanding how the Stock module actually thinks. Honestly, most "ERPNext showed wrong stock" tickets I have seen trace back to a manual quantity edit that skipped the ledger, not a flaw in the product.
What is ERPNext inventory management?
ERPNext inventory management is the Stock module inside the wider ERPNext platform. Every physical movement of goods becomes a saved document, and each document simultaneously updates the quantity on hand and the monetary value of stock. Because stock and accounting share one database, the warehouse balance and the general ledger never drift apart.
The design principle worth internalising early is that you almost never type a stock number directly. You record a transaction — a receipt, an issue, a transfer — and the system derives the balance. That is why a spreadsheet-style "just set the count to 40" edit causes so much grief. The correct tool for a physical count correction is a Stock Reconciliation, which posts a proper adjustment entry.
One module, many entry points
Stock updates flow in from Buying (Purchase Receipt), Selling (Delivery Note), and Manufacturing (Stock Entry against a Work Order). You do not manage inventory in isolation — it is the shared ledger every other module writes to.
Skimmable summary: ERPNext inventory is transaction-driven — you record movements, and the system derives every balance and value.
How do warehouses work in ERPNext?
Warehouses in ERPNext are organised as a tree, not a flat list. Parent warehouses act as groups, and leaf warehouses hold actual stock. That structure lets a single company represent a main godown, cold storage, a quarantine bin, and several branch locations while still rolling everything up into one consolidated view.
Each leaf warehouse can be mapped to a general-ledger account. When perpetual inventory is switched on — the recommended mode — every movement in or out of that warehouse posts a matching accounting entry, so your books always reflect real stock value. You can also transfer stock between warehouses with a single Material Transfer Stock Entry, which keeps total company stock unchanged while moving quantity from one location to another.
| Warehouse capability | What it gives you |
|---|---|
| Tree hierarchy | Group branches, bins, and zones under one company |
| GL account mapping | Perpetual inventory keeps stock value and books aligned |
| Inter-warehouse transfer | Move stock without changing total on-hand |
| Warehouse-wise reorder | Different reorder rules per location |
For distribution businesses juggling many godowns, this hierarchy is the backbone of clean multi-location control. I cover that scenario in more depth in the guide on ERPNext for distributors and wholesalers in India.
Skimmable summary: Warehouses are a tree of locations, each mappable to a GL account, with transfers that preserve total stock.
Which stock valuation method should I use — FIFO or moving average?
Stock valuation in ERPNext is set per item, and the two everyday choices are FIFO and moving average. FIFO keeps a queue of cost layers: each receipt adds a layer at its actual incoming rate, and each issue consumes the oldest layers first at their original rates. Moving average instead recalculates a single blended rate every time new stock arrives.
Neither method is universally "correct" — the right pick depends on the goods. FIFO suits items where cost genuinely moves in batches, like imported components or perishables, because it reflects the specific cost of what left the shelf. Moving average smooths out price volatility and is simpler to reason about for fast-moving, uniform stock. ERPNext maintains the layers and the running rate for you; you just choose the method on the Item.
Set valuation before transactions
Change the valuation method on an item only when its stock is nil. Switching FIFO to moving average with live quantity on hand creates confusing restatements. Decide during setup, not after go-live.
Skimmable summary: Choose FIFO for batch-costed or perishable goods, moving average for uniform fast-movers — and lock it in before transactions begin.
How do batch and serial numbers work?
Batch and serial tracking are optional per-item settings that add traceability. A batch groups a quantity of identical units produced or received together — think a pharma lot with an expiry date, or a dye lot of fabric. A serial number identifies one individual unit, which suits high-value or warranty-bound goods like machinery, electronics, or instruments.
Once enabled, ERPNext asks for the batch or serial at every relevant transaction, so you always know which lot or unit moved where. That underpins recalls, expiry management, and warranty lookups. Newer ERPNext releases add a Serial and Batch Traceability report that lets you trace backward — which raw materials and batches went into a finished product — or forward, to every customer or location a batch reached.
Use batches when
Units are interchangeable but grouped by lot, expiry, or manufacturing run. Common in food, pharma, chemicals, and textiles.
Use serials when
Each unit is individually identifiable and you need per-unit warranty, AMC, or history. Common in machinery, electronics, and instruments.
If your batches originate on the shop floor, the way you configure production feeds directly into traceability — see how bills of materials drive this in the ERPNext multi-level BOM guide.
Skimmable summary: Batches track grouped lots (expiry, run); serials track individual units (warranty) — both give full backward and forward traceability.
How does reorder level and auto-reordering work?
Reorder level is a threshold you set on an item — or on a specific item-warehouse combination — below which ERPNext acts automatically. When projected quantity falls to that level, the system can raise a Material Request without anyone watching the shelf. You also define the reorder quantity and whether the next step is a fresh purchase or a transfer from another warehouse.
Projected quantity, not just physical stock, drives the trigger. It accounts for what is already ordered, reserved, and requested, so ERPNext does not double-order goods that are simply in transit. Users with the relevant purchasing role receive an alert when a reorder-driven Material Request is created, closing the loop between the warehouse and the buying desk.
Set the threshold
On the Item (or its warehouse row), enter Reorder Level and Reorder Qty.
Choose the action
Pick whether a shortfall creates a purchase request or an internal transfer.
Let ERPNext watch
A scheduled job checks projected quantity and auto-creates Material Requests when stock dips below the level.
Convert to order
Purchasing turns the Material Request into a Request for Quotation or Purchase Order.
Skimmable summary: Set a reorder level and quantity; ERPNext watches projected stock and auto-raises Material Requests, then alerts your buyers.
Which stock reports matter most?
Stock reporting in ERPNext ships as ready-made reports, so most businesses never need custom development to see their inventory clearly. The four I lean on daily answer distinct questions: what do I have, what happened, what will I have, and what is stuck. Knowing which report answers which question saves hours of confusion.
Stock Balance shows item-wise, warehouse-wise quantity and value across all transactions. Stock Ledger is the transaction-by-transaction audit trail behind those balances. Stock Projected Qty layers in ordered, reserved, and requested amounts to show where you are heading. Stock Ageing surfaces slow-moving inventory so working capital is not silently trapped on a shelf.
| Report | Question it answers |
|---|---|
| Stock Balance | What quantity and value do I hold right now, by warehouse? |
| Stock Ledger | Exactly which transactions moved this item, and when? |
| Stock Projected Qty | After open orders settle, where will my stock land? |
| Stock Ageing | Which stock is old and tying up cash? |
When Stock Balance and a physical count disagree, the fix is a Stock Reconciliation — a document that adjusts quantity and value with a proper ledger entry, never a silent overwrite.
Skimmable summary: Stock Balance (now), Stock Ledger (history), Projected Qty (future), and Stock Ageing (dead stock) cover almost every inventory question.
How does ERPNext inventory compare to standalone stock tools?
ERPNext inventory differs from bolt-on stock apps in one structural way: it is not a separate system that syncs with your accounts — it is part of your accounting, buying, selling, and manufacturing platform. That removes the reconciliation gap that plagues businesses running a billing tool beside a disconnected inventory app.
| Dimension | ERPNext Stock module | Standalone inventory tool |
|---|---|---|
| Licence model | Free, open source (GPLv3) | Varies — often per-user subscription |
| Accounting link | Native, single database | Usually a separate sync or export |
| Manufacturing | Built-in BOM, Work Orders, subcontracting | Often absent or add-on |
| Customisation | Full source access, own fields | Vendor-limited |
| Multi-warehouse | Tree hierarchy, per-location reorder | Varies by product |
Pricing across editions and hosting varies by vendor, so always check the official page rather than a blog figure. What ERPNext removes is the category of cost that comes from two systems disagreeing. If your inventory feeds a factory, the tie-in with production is where this integration pays off — I unpack that in the piece on ERPNext manufacturing in India.
Skimmable summary: ERPNext inventory is one database with accounting and production, not a separate app you reconcile — its licence is free and open source.
Frequently asked questions
Is ERPNext inventory management free?
Yes. ERPNext, including its Stock module, is free and open source under the GPLv3 licence, with no per-warehouse or per-item fee for the software itself. Costs you may incur are for hosting, implementation, or support — pricing for those varies by provider, so check the vendor's official page.
Can ERPNext track stock across multiple warehouses?
Yes. Warehouses are organised as a tree, so one company can hold a main godown, cold storage, quarantine bins, and multiple branch locations, each reporting into a consolidated view. You can transfer stock between them and set warehouse-specific reorder rules.
What stock valuation methods does ERPNext support?
ERPNext supports FIFO and moving average valuation, chosen per item. FIFO consumes the oldest cost layers first; moving average blends a single running rate on each receipt. The system maintains the underlying layers and rates automatically once you pick a method.
How does ERPNext handle expiry and traceability?
Enable batch tracking on perishable or lot-controlled items and record a batch (with expiry) at each transaction. For individually identifiable goods, enable serial numbers. Newer releases add a traceability report to trace materials backward into a product or forward to every customer a batch reached.
What is perpetual inventory in ERPNext?
Perpetual inventory is a company setting that posts an accounting entry for every stock movement, using the GL account mapped to each warehouse. It keeps stock value and the general ledger continuously aligned and is the recommended mode for most businesses.
How do I correct a wrong stock quantity in ERPNext?
Use a Stock Reconciliation document, not a direct edit. It records the physical count and posts a proper adjustment to both quantity and value in the stock ledger, preserving the audit trail. Avoid overwriting numbers in a way that skips the ledger.
About the author
Manoj is an ERPNext implementation consultant at Mith Tech, an independent open-source ERPNext and Frappe studio in Bengaluru. He works with Indian SMBs on stock, manufacturing, and distribution setups, and writes about the practical decisions that make or break an ERPNext go-live.
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