The POS vs inventory management system question has a short answer for most small shops: you need one system that does both jobs. A POS records what leaves through the till, and an inventory system records everything else your stock does. The real test is whether your POS records stock arriving, moving and spoiling, as well as selling.
This guide draws the line between the two on one carton of soap. It then gives five questions that settle it for your shop, and the cases where a separate system pays.
What is the difference between a POS and an inventory management system?
A POS records sales and payments at the counter, while an inventory management system records stock wherever it is and however it moves. Investopedia describes inventory management as ordering, storing, using and selling stock. A till-only POS covers one of those four verbs.
| Question | POS | Inventory management system |
|---|---|---|
| Main job | Ring up the sale and take payment | Know what you hold, where, and what it cost |
| Who uses it | Cashiers, all day | The owner or store keeper, at deliveries and counts |
| Stock goes down when | A sale is made | A sale, a transfer, a damage or a count says so |
| Stock goes up when | A customer returns an item | A supplier delivers, a transfer arrives, or a count finds more |
| Main report | Sales and payments by method | Stock value, low stock, slow and dead stock |
Most POS systems today carry some inventory features, so the labels blur. What matters is which of the rows on the right your system actually records.
Where a POS ends: one carton of soap, followed
A till-only POS sees two of the eight things that happen to a carton of stock. The worked example below shows the gap that leaves.
For example, a shop in Nairobi, Kenya, buys a carton of 24 bars of soap on credit, at KES 1,800, or KES 75 a bar. It keeps the carton in a store room and sells the bars at the counter for KES 100 each.
| Event | Bars held after it | Till-only POS records it? | Inventory system records it? |
|---|---|---|---|
| 1. Carton delivered, KES 1,800 owed to the supplier | 24, all in the store room | No | Yes: purchase and supplier debt |
| 2. Carton opened into 24 single bars | 24 | No | Yes: unit conversion |
| 3. 12 bars moved to the shop shelf | 24: 12 store room, 12 shelf | No | Yes: transfer |
| 4. 10 bars sold at KES 100 | 14 | Yes | Yes |
| 5. A customer returns 1 bar | 15 | Yes | Yes |
| 6. 2 bars found wet in the store room | 13 | No | Yes: damage, KES 150 written off |
| 7. Count finds 1 bar missing from the shelf | 12 | No | Yes: adjustment |
| 8. Shelf drops to its alert level | 12 | No | Yes: reorder alert |
Even if someone typed in the 24 bars by hand, the till-only POS now believes the shop holds 15. It holds 12. The 3-bar gap is KES 225 at cost, and nobody sees it until the next count.
The bigger cost is the supplier. Without event 1, the KES 1,800 debt lives in a notebook, and the profit report has no cost to set against the sales.
Our guide to inventory management for small businesses covers each of these records in turn.
Five questions that decide whether your POS is enough
Your POS is enough if it answers yes to every question your shop needs. Each no is a job you will keep doing in Excel or an exercise book.
- Can stock come in any way other than a sale? A purchase should add stock, record the cost and show what you owe the supplier.
- Does it count in cartons and pieces? You should be able to buy by the carton and sell by the piece without converting by hand.
- Does it know where the stock is? The shop front, the store room and a second branch each need their own count.
- Can you count, adjust and write off, with a reason? Damage and theft should show as their own lines, not vanish into sales.
- Does it track what expires or carries a serial number? Pharmacies, food shops and phone shops need batches, expiry dates or IMEI numbers.
Low-stock alerts follow from these. A POS that knows the true count can warn you before the shelf empties, as in how to avoid overstocking and stockouts.
When a separate inventory management system is worth it
A separate inventory system pays when stock work is a business of its own, not a corner of a shop. Three cases qualify.
- You make what you sell. Turning raw materials into products needs bills of materials and production records. See our guide to raw materials inventory.
- You run a warehouse that picks and ships for others. That is warehouse management, a different job: inventory vs warehouse management.
- Your accounts already run on an ERP. Then the ERP holds the stock, and the POS should feed it: POS vs ERP.
For a shop, two systems usually cost more than they give. Every new product, price change and count happens twice, or through a sync that can fall out of step. When the internet drops, the till and the stock system disagree until someone reconciles them.
Where your stock lives also matters. A cloud system lets the owner see every branch from one phone: our comparison of cloud and on-premises inventory systems sets out the trade-offs.
How ArmPOS covers both in one system
ArmPOS is a point of sale system with the inventory side built in, so each of the eight soap events has a place. Here is where each one goes, with its Help center guide.
- The delivery: record a purchase with the supplier and the warehouse; status received adds the stock: Record a purchase from a supplier. What you owe shows in Pay your suppliers.
- Cartons and pieces: make a Box unit built on Piece, and buy by the box while selling by the piece: Categories, brands and units.
- Store room and shop: on a plan with two or more warehouses, each can be its own warehouse. Racks and shelves become its locations: Your warehouse and its locations. A transfer moves stock once someone approves it: Move stock between warehouses.
- Sales and returns: the POS takes stock off, and a return puts it back: Returns and refunds.
- Spoiled goods: record a damage, kept apart from adjustments: Record damaged or spoiled stock.
- The count: download a count sheet by warehouse and category, then adjust by the difference: Count and adjust stock.
- The reorder: set a Stock Alert on each product; the Product Quantity Alerts report lists what to reorder: Reports to check every day. The bell warns you too, and so do push or email alerts for each person who switches them on: Get alerts on your phone.
- What it is worth: the Inventory Valuation, Dead Stock and Stock Aging reports: Stock reports.
Frequently asked questions
Can a POS system manage inventory?
Yes, if it records stock coming in, moving and being written off, as well as sales. Run the five questions above in a free trial to find out.
Do I need both a POS and an inventory management system?
Most small shops need both jobs done, but not two products. Buy a second system only if you manufacture, run a fulfilment warehouse, or keep your stock in an ERP.
Is inventory management the same as warehouse management?
No. Inventory management tracks how much you hold and what it cost, while warehouse management runs the work inside a warehouse, such as picking and packing.
What does a POS system do that an inventory system doesn't?
It runs the checkout: totals, discounts, split payments, receipts and the cash drawer. An inventory system on its own can't take the customer's money.
Test it on your own stock. Create a free ArmPOS account, record one carton as a purchase, and follow it from the store room to the receipt.
