RFID vending machines — how they work and what they cost you
RFID, camera or weight sensors: how each identifies what a customer took, where RFID wins, and the tagging cost suppliers rarely put in writing.
Every smart cabinet has to answer one question: what did the customer just take? There are three ways to answer it, they behave differently, and the choice decides what you can sell and what your operating cost looks like. This page explains how RFID works, where it wins, and where it costs you more than the alternatives — including the part suppliers rarely put in writing.
How does an RFID cabinet work?
- Each item carries an RFID tag, so the cabinet knows its contents item by item — not shelf by shelf, and not by silhouette.
- The customer authenticates at the payment terminal and the door unlocks.
- They take what they want and close the door. Nothing is dispensed, nothing drops.
- The cabinet reads its contents again and the charge is built from the difference.
- Stock, sales and expiry dates are visible remotely, so restocking is scheduled rather than discovered.
The part that matters commercially is the second-to-last line. Because nothing is dispensed, the cabinet can hold salads, sandwiches, yoghurt, fresh meals and soft packaging — the products a spiral machine destroys. That single mechanical fact is why fresh food is possible at all.
The three technologies, compared honestly
Suppliers of each technology claim theirs is the most reliable, and you will find confident statements in both directions. Rather than repeat any of them, here is what each approach actually does and what it asks of you in return.
RFID tags
- Identifies products individually, so two similar items are never confused.
- Works when items are stacked, turned over, put back in the wrong place or moved by a customer who changed their mind.
- Knows expiry dates per item, which is what makes date-based discounting an actual tool rather than a slogan.
- Requires every item to be tagged. This is the real cost and it is discussed below.
Camera and computer vision, often sold as "AI vending"
- No tagging, so nothing is added to the product handling chain.
- Depends on the item being visible and visually distinctive — which is exactly what packaging variants, promotional sleeves and a hand in the way interfere with.
- Does not inherently know an individual item, so it does not know that item's expiry date. It knows the product type.
Weight sensors
- Simple and the cheapest to build.
- Struggles to distinguish products of similar weight, which is common in drinks and snacks.
- Sensitive to placement: an item resting across two shelf zones reads as ambiguous.
What RFID actually costs you — the part that is usually left out
RFID's accuracy comes from the tag, and the tag has to get onto the product. Someone has to do that, for every single unit, before it reaches the cabinet. That is a labour step and a per-unit cost, and it does not go away as you scale — it scales with you.
The consequence is a margin question, not a technical one. On a sandwich or a ready meal, the tag is a small fraction of the price and the accuracy is worth it. On a low-priced item — a piece of fruit, a single snack bar — the tag can eat a meaningful share of the gross margin. If your assortment is mostly low-priced units, model that cost before you commit, because it changes which products are worth stocking.
This is also where the tagging question becomes a supply-chain question rather than an operations one. If tags can be applied upstream, at the packer, the labour disappears from your route. If they cannot, it stays on your route forever. Ask this early; it is one of the few decisions that is hard to reverse.
Which technology fits which assortment?
- Fresh food with short shelf life: item-level expiry matters, and that points to RFID.
- Drinks and packaged snacks of similar size: the tagging cost is proportionally higher, and camera or weight becomes more competitive.
- Non-food items and mixed assortments: item-level identification is usually worth more than the tag cost, because the products differ too much for a silhouette.
- Unstable environments — variable light, cramped installs, frequently changing packaging: tags do not care about any of that.
Hybrid units combining approaches exist in the market. We are not describing how they perform, because we have not tested them and a claim about someone else's hardware is not ours to make.