Zara’s self-checkouts work because almost every garment carries a small radio tag inside its label or security tag, and the terminal reads all of those tags at once rather than one at a time. You put the pile down without unfolding anything or hunting for barcodes, the screen fills with your items a second later, you check the list and you pay.
That is the short answer. The longer one matters, because the same tags are doing other jobs while you stand there, and because Inditex, the Spanish group behind Zara, Bershka, Pull&Bear and Lefties, has been careful about which parts of the system it describes in public. It reported 5,444 stores across 215 markets in its interim results on 9 September 2026.
What is in the label
The technology class is passive UHF RFID, sold under the industry name RAIN RFID. Passive means no battery: the tag is a printed aluminium antenna and a chip the size of a grain of sand, powered by the radio energy the reader shines at it. UHF means ultra high frequency, here 860 MHz to 960 MHz, which gives a range of metres rather than centimetres. Our RFID glossary covers the rest of the vocabulary used below.
What matters is what is on the chip. A barcode says what kind of thing an item is: a size 12 black linen shirt at 29.99. An RFID tag says which one it is: a serial number unique to that shirt out of hundreds of identical ones. That is why RFID is a stock system first and a checkout convenience second.
Be precise about what Inditex has said
This is where most writing about Zara’s technology goes wrong. Inditex names RFID directly in its annual reporting, but in the context of stock rather than tills. Its 2023 annual report says that “by adopting and developing technologies such as Radio Frequency Identification (RFID) or the Integrated Stock Management System (SINT), we have merged the inventory management of all our brands”, so that “our staff can quickly locate any article, regardless of where it is located”. The same chapter says “all our physical stores and online platforms are merged into a single sales environment”.
The newer programme, which replaced the hard plastic alarm tag on Zara garments, is what the group calls its “soft tag alarm technology”. Its FY2024 results on 12 March 2025 said the system was “now fully operational in Zara” and would reach Bershka and Pull&Bear that year. Its FY2025 results on 11 March 2026 said “the hardware is now in 100% of our physical stores” and that the initiative “complements the Assisted Checkout programme”. By September 2026 the wording was “the new soft-tag technology has now been implemented in all of our stores”.
Notice what is absent. Inditex has not published the radio inside the soft tag, its frequency, its read range, its chip or who makes it, and it has not named the makers of the readers or the terminals. Anyone who tells you the make and model of the tag in a Zara shirt is guessing. What the group has confirmed is the shape of the system: a soft tag carrying the alarm function, a checkout programme alongside it, and an inventory system it has elsewhere described as built on RFID.
How a terminal reads a pile of clothes at once
A barcode scanner needs to see the barcode. A radio reader does not need to see anything, which is the whole point. It floods the bay with a radio field, and every tag in range harvests enough energy to reply with its serial number. Fabric and paper are effectively transparent at these frequencies, so a tag folded inside a jumper at the bottom of the stack answers as readily as the one on top. The same technology runs at far greater scale in our Decathlon case study, where a RAIN tag goes on every product the retailer sells.
Once the list matches what you are holding, the payment is ordinary: card, contactless, phone or the app. The tag side is what changes. In the hard-tag era a cashier pulled a plastic tag off with a magnet; with a soft tag there is nothing to remove, so the system records that these serial numbers have been sold, taking them out of the store’s stock figure and stopping them triggering an alarm on the way out. How Zara does that is not public: the chip can have a security bit flipped, or the door reader can check what it sees against recent sales.
The security question, answered properly
People searching for how this works often ask whether Zara’s sensors use tags to detect theft, which merges two technologies. The gates at a shop door are electronic article surveillance, or EAS, and they are deliberately stupid. As we explained in our piece on what the hard plastic tag on clothes actually does, an EAS tag carries no identity: it is a tuned circuit resonating at one fixed frequency, and the gate learns one fact, that something live went past. RFID is the opposite, because it identifies the individual item, so an exit reader can say which garment left and whether it was paid for. We covered that distinction in RFID for loss prevention.
The trade-off is physical rather than technical. A hard tag is hard to remove on purpose; a soft label a customer is happy to carry home is also one a thief can pick off. In 2023, Bloomberg reported that the group had delayed a planned rollout of RFID-based anti-theft tagging across Zara after testing showed the chips in garment labels were easy to remove, and that it was examining a tag wrapped in textile yarn and sewn into a seam instead. Inditex said at the time that implementation was “going according to plan, without any significant incidents”. We set out the detail in our Lefties coverage from 27 August 2026.
The group’s own term, “soft tag alarm technology”, tells you the alarm function now rides on the soft tag rather than a plastic clip. It does not tell you the radio inside it, and it does not mean conventional EAS has gone everywhere.
What the tags do behind the counter
The checkout is the visible tip of the system, not the part that pays for it. Because every item has a serial number a reader can find without unpacking anything, staff can walk a handheld reader around the shop floor and stockroom and produce a full count in hours rather than days. Our case study on Zara’s RFID-powered fast fashion machine sets out what that bought the retailer, including inventory accuracy moving from around 65 per cent before tagging to above 95 per cent after it.
Accuracy at that level changes what a retailer can promise. It is why a store can sell its own shop floor stock to an online customer: a figure right to within a few per cent is safe to expose to a website, and one right two thirds of the time is not. It is also the basis for click and collect and ship from store, covered in our explainer on RFID and omnichannel retail.
What a shopper can see
Not much, which is intentional. The tag is a flat paper or plastic label, often behind the care label or inside the swing ticket, with a visible aluminium pattern if you hold it to the light. There is no battery, no GPS and no personal data: the chip holds a serial number and is inert the moment it leaves a reader’s field. Reads are good rather than perfect: metallic thread, foil-backed packaging or a wet garment can cost a read, which is why the terminal asks you to confirm the list.
The open questions are worth stating plainly. Inditex has not published the soft tag’s specification, how many of its checkouts are self-service, or how much shrinkage the arrangement prevents. Reporting of its earnings-call commentary has put self-checkout at up to around 90 per cent of transactions in some of its largest stores, excluding app payments, but that covers selected shops rather than the group. The direction is clear: the group told investors the soft tag will be “the basis for us to continue deepening the digitalisation of stores and their integration with online platforms in the coming years”. More in our explainer on RFID in fashion and apparel, and more coverage in Retail and Fashion.
