For most shops, wholesalers and distributors, stock is the biggest amount of money tied up in the business, often more than the cash in the bank. Yet many businesses manage it with memory, a notebook and an occasional count. This guide explains what inventory management is, the movements you need to track, and what happens when it goes wrong.
Inventory management is the process of knowing what stock you have, where it is and how much it is worth, and making sure you have the right amount to meet demand without tying up too much cash. It covers buying stock, receiving it, storing it, selling it, moving it between locations and correcting the records when reality differs.
In practice it answers four daily questions: What do we have? What is selling? What should we reorder? Where is our money sitting?
Your stock level changes only when something happens. If every one of these events is recorded, your stock numbers stay accurate.
| Movement | Effect on stock | Example |
|---|---|---|
| Purchase / goods received | Increases | A supplier delivers 50 cartons of drinking water |
| Sale | Decreases | A customer buys 2 cartons at the counter |
| Customer return | Increases (if resaleable) | A customer returns an unopened item |
| Return to supplier | Decreases | A damaged batch is sent back |
| Transfer | Decreases one location, increases another | 20 units moved from the warehouse to the shop |
| Adjustment | Increases or decreases | Correcting for breakage, expiry, theft or counting errors |
The most common cause of wrong stock numbers is a movement that happened physically but was never recorded: goods received without paperwork, items taken for personal use, or breakage thrown away.
Good inventory management starts before goods arrive. Create a purchase order when you order, so you know what is coming and at what cost. When the delivery arrives, check quantities against the order and the supplier's invoice, then record what you actually received. That keeps both your stock and the amount you owe the supplier accurate.
When your POS is connected to inventory, each sale reduces stock automatically and you never need to update stock by hand after selling. See What is a POS system? for how this works. Returns should be recorded against the original sale, so both revenue and stock are corrected.
If you have a warehouse and a shop, or several shops, record stock separately for each location. When stock moves, record a transfer. Without this, total stock may be right but you won't know where it is, and staff waste time looking for items or customers are told "out of stock" while boxes sit in the back.
Even good systems drift. Breakage, expiry, theft and simple mistakes happen. Regular counts compare the system with the shelf:
When a count shows a difference, record an adjustment with a reason. Over time, the reasons tell you where losses come from. Our article on preventing inventory mistakes shows how to investigate differences.
A reorder level (or alert quantity) is the stock level at which you should place a new order. A simple way to set it:
Reorder level = average daily sales × supplier delivery time (days) + safety stock
For example, if you sell 8 bottles of cooking oil a day, your supplier takes 4 days to deliver, and you keep 10 bottles as a buffer, your reorder level is 8 × 4 + 10 = 42 bottles. When stock falls to 42, you reorder. For more on everyday stock habits, see Stock control basics for shops.
Keep supplier contacts, what you buy from each, typical prices and delivery times, and how much you owe them. That helps you compare suppliers, plan payments and negotiate when you can show your purchase history.
Stock is money on shelves, so it helps to know what it's worth. The simplest measure is stock value at cost: quantity on hand × the price you paid. Costs change over time, so systems use a method to decide which cost applies. Common ones are average cost (cost averaged across purchases) and FIFO (first in, first out, where the oldest units are assumed sold first). Your accountant can advise which suits your reporting; the important thing is to use one method consistently.
A notebook or spreadsheet can work for a small range of products and one person updating it. As products, staff and locations grow, manual records fall behind. We compare the two honestly in Inventory software vs Excel.
In KyeFlow, sales, purchases and returns update stock automatically. Products can have variants, batches and expiry dates, and alert quantities show what needs reordering. Stock counts, adjustments and transfers between locations are included in the Standard and Premium plans, along with inventory reports.
Key takeaways
In everyday business use the words mean the same thing: the goods you hold to sell. Some accountants also include raw materials and work in progress in "inventory".
Count fast-moving or high-value items weekly or monthly with cycle counts, and do a full count at least once a year.
The stock quantity at which you should place a new order. It is usually based on daily sales, supplier delivery time and a safety buffer.
Yes. Software is most useful when stock updates automatically from sales and purchases, which saves time even for a single small shop.
Want sales and stock in one place? See how KyeFlow updates inventory with every sale and purchase. Explore KyeFlow.
