Inventory management for a small business comes down to five habits: keep one accurate record per item, update it every time stock comes in or goes out, reorder at a calculated point rather than by eye, count regularly in small batches, and review what isn't selling. Software makes each habit automatic, but the habits matter more than the tool.
Inventory is usually a small business's biggest asset after cash — and the one most likely to be wrong. Too little and you lose sales; too much and cash sits on shelves. This guide covers the fundamentals in plain terms, with links to deeper guides on each topic.
1. One record per item
Every product you sell needs a single "item master" record. At minimum:
| Field | Why it matters |
|---|---|
| Name and SKU or barcode | Identifies the item without ambiguity |
| Unit (piece, kg, box) | Stops counting errors between buying and selling units |
| Purchase cost and selling price | Margin and stock valuation |
| Tax rate and HSN/SAC code | Correct invoices and returns |
| Reorder point and lead time | Knowing when to buy |
| Location (shop, warehouse, rack) | Finding it quickly |
2. Record every movement
Stock changes for only a handful of reasons: purchases, sales, returns, transfers between locations, and adjustments (damage, expiry, theft, count corrections). If every one of those is recorded — with a date and reason — your current stock is simply the sum of the movements. This running history is called a stock ledger, and it's what lets you explain any number later.
3. Reorder at a calculated point
Reorder point = (average daily sales × supplier lead time) + safety stock. A flat "reorder at 10" rule leaves fast sellers running out and slow sellers overstocked. Our guide to setting reorder points has worked examples, and simple demand forecasting shows how to estimate daily sales.
4. Count little and often
Instead of one painful annual count, count your most valuable items weekly, the middle group monthly, and the rest quarterly — a method called cycle counting. ABC analysis tells you which items are which, and our one-hour stock audit guide covers the process.
5. Watch what isn't selling
Items with no sales in 90 days are tying up cash and space. Review them monthly and clear them before they lose more value — see dead stock: how to spot and clear it. Holding stock typically costs 15–30% of its value per year (holding cost explained).
Valuing your stock: FIFO vs weighted average
| Method | How it works | Good for |
|---|---|---|
| FIFO (first in, first out) | Oldest purchase cost is used first when items are sold | Perishables, items with changing purchase prices |
| Weighted average | Each sale uses the average cost of all units on hand | Commodities and items bought repeatedly at similar prices |
Pick one with your accountant and apply it consistently — switching methods between years makes profit figures hard to compare.
Five numbers worth tracking
- Stock value — what your inventory is worth at cost today
- Inventory turnover — cost of goods sold ÷ average stock value; higher means stock moves faster
- Days of stock on hand — how long current stock would last at today's sales rate
- Stockouts — how often a sellable item hit zero
- Shrinkage — the gap between recorded and counted stock
Notebook, spreadsheet, or software?
| Notebook | Spreadsheet | Inventory software | |
|---|---|---|---|
| Cost | None | None | Free tiers available |
| Stock updates | Manual | Manual | Automatic on every sale and purchase |
| Barcode scanning | No | No | Yes |
| Reorder alerts | No | Only if you build them | Built in |
| Works for a team | Hard | Version conflicts | Separate logins |
A notebook or spreadsheet is fine for a small, slow catalogue. Once you're reconciling stock against invoices every month or running out of best-sellers, it's time to move — see Excel vs dedicated inventory software.
StashBill (launching soon) is inventory management software built around these habits: scan to record every movement, automatic reorder and dead-stock alerts, and a full stock ledger — see all features.
Frequently asked
What is the simplest way to start managing inventory?
List your top 50 items with their current count, cost, and selling price, then record every sale and purchase against them. Expand the list as you go.
How often should a small business count stock?
High-value items weekly or fortnightly, the rest monthly or quarterly, with one full count a year — usually at financial year-end.
What is a good inventory turnover ratio?
It varies by trade — grocery turns stock many times a year, hardware far fewer. Compare yourself with your own previous periods and aim for steady improvement.