RFID readers: which type fits, and what it costs.

What an RFID reader is and how it works

The carrier signal

The reader first sends an unmodulated wave, the carrier. This wave does two jobs at once: it carries energy to the tag, and it serves the tag as a carrier for its answer. A passive tag has no transmitter of its own. It rectifies the radio frequency it receives, charges a tiny capacitor and uses that to switch on its state machine. If the energy is not enough, the tag stays silent — that is the real reason why range in RFID has no sharp edge, but a field with soft margins.

Backscatter instead of transmitting

For its answer the tag switches the impedance of its antenna in time with the data. Sometimes the antenna matches the chip, sometimes it does not, and more or less energy is reflected accordingly. The reader sees that as a tiny change of amplitude in its own signal. Because the reflected signal is orders of magnitude weaker than the transmitted one, the real effort in a good reader sits not in the transmit path but in the receiver and in the isolation between the two paths.

Anti-collision under EPC Gen2

Single tags are rare in the field. On a full rail hundreds answer at once, and with no rule in place they would wipe each other out. EPC Gen2, standardised as ISO/IEC 18000-63, resolves that with a slotted random procedure, the slotted ALOHA principle:

• The reader opens an inventory round and sets a number of time slots, the Q value.
• Every tag picks a slot at random and stays silent until that slot comes round.
• If exactly one tag answers in a slot, the reader acknowledges it and reads out its EPC.
• If several answer, they collide; the reader raises the Q value and starts a new round.
• Tags that have been read are set to a different state and do not report again in the same inventory round.

Good readers track the Q value automatically. This procedure is exactly why a full rail can be counted in seconds, while the barcode demands that every item be picked up one at a time.

From the sled to the stocktaking robot

Sled on a smartphone

A sled is an RFID module with its own battery, antenna and trigger, into which an existing smartphone is clipped. The link runs over Bluetooth or over a plug contact. The advantage: the display, the camera and the computing power are there anyway, the device is light, and the user interface is the familiar app. The drawback: two batteries, two devices, and a private phone is rarely as rugged as an industrial one.

Mobile terminal with a pistol grip

The classic for counting larger floors. Display, computer, RFID module and antenna sit in one housing, and the grip takes weight off the wrist and forearm. These devices are built for drop heights of about one and a half metres and run a full working day. They are the heaviest and dearest mobile type, but the most comfortable one when somebody walks the shop for two hours at a stretch.

Compact Android terminal without a grip

A smartphone-like device with a built-in UHF module, usually 200 to 350 grams. Range and read rate sit below those of a pistol-grip device, but for a shop with a few thousand items that is enough. If you already run a mobile till or a customer advice app on the same device, you save yourself a second one.

Fixed reader

A stationary device in control-cabinet format with two to eight antenna ports, Ethernet and usually some filtering logic of its own. The fixed reader is the basis for every fixed application: gate, tunnel, shelf, conveyor. Without matching external antennas it is useless — the choice of antenna decides the result.

RFID gate at the exit

Two antenna panels to the left and right of the doorway, with a fixed reader behind them. A gate records every tag carried through it and reports it to the software. Typical applications are goods out, goods in at the loading bay, and theft detection. A gate is not a till: it does not know whether an item has been paid for, only that it has crossed the line. The software makes that distinction.

Tunnel and desktop readers

A tunnel reader is a shielded tube over a conveyor belt; a desktop reader is a shielded tray or plate. Both deliberately limit the read field so that only the goods inside the device are recorded and not the box beside it. That containment is precisely their value: they give unambiguous results where an open field constantly reads the neighbours as well. In retail they make sense for checking whole boxes at goods-in and for encoding new labels.

Smart shelf

Antennas are built into the bases or back panels of shelving and polled in cycles. The result is stock almost in real time, without anybody doing anything. The price for that is high: antennas, cable and a reader per shelf metre, plus an installation that changes the shop fittings. On small floors the effort is usually out of proportion to the benefit. A smart shelf becomes worthwhile with a small number of very high-value articles.

Stocktaking robot and drone

A rolling robot with UHF antennas drives the floor at night and counts. Systems like this are in use at large chains and give daily stock figures without staff time. The purchase, though, runs into five to six figures and calls for clear driving lanes and well-kept shop fittings. For a boutique or a sports retailer it is not an option; it is worth mentioning because it shows where fixed-site recording is heading.

Types compared

Price ranges are guide values for the European market, net of VAT, without software, labels and services. Project prices sit below them, depending on quantity and dealer.

Specific devices and list prices

Net list prices as at 2026, source: specialist dealers. Prices exclude VAT, accessories such as a charging cradle, a spare battery or a hand strap, and any software licence; business buyers elsewhere in the EU holding a valid VAT identification number are invoiced under the reverse-charge procedure. List prices are regularly undercut in project business; with a sled the host device comes on top.

What comes on top of the device price

• Charging cradle and spare battery: around 100 to 300 euro, depending on the device.
• Software: without an application the reader counts numbers, not articles.
• Labels: passive UHF labels cost around 12 to 15 cents in small quantities.
• Label printing: an RFID printer for labelling in the shop.
• Set-up: the link to the till system, master data matching, instruction.

In practice the reader is rarely the largest item. In a shop with 4,000 items the labels cost around 500 to 600 euro in the first year, the device costs a four-figure sum once, and the running software sits in two figures a month with providers such as HANGCOUNT. Compare hardware prices alone and you are comparing the smaller part of the bill.

Read performance: tags per second, items per minute

Why laboratory figures and shop figures differ

Datasheets quote peak values, measured with evenly laid-out tags in free air, without metal, without people, at an optimal angle. In the shop items lie stacked tightly, tags shadow one another, steel hangers and shelving distort the field, and goods with a high water content swallow energy. What is realistic, therefore, are figures that take in the whole walk across a floor, not the radio performance alone.

What sets the read rate in practice

• Antenna orientation. A tag whose dipole lies across the polarisation is read badly or not at all. Circularly polarised antennas soften that, but cost range.
• Tag density. The more tags are in the field at once, the more collision rounds the Gen2 procedure needs. Throughput does not fall linearly, but it falls.
• Surroundings. Metal shelving reflects, and so do mirrors and glass fronts. Zones of very good and zones of poor field strength arise.
• Transmit power and sensitivity. Both are capped on European devices; differences arise above all in the receiver.
• Walking speed. Walk too fast and you leave the reader too few inventory rounds per shelf metre. Two calm passes are better than one hasty one.

Working with realistic figures

An example: a shop carries 4,000 items over 120 square metres. At around 700 items per minute the recording alone takes just under six minutes. With a second pass, the stockroom, the window display, the fitting room and the clearing up of discrepancies, you land at one to two hours in practice for the complete stocktake. For comparison: the same floor by barcode costs two people a day.

Transmit power and the law in Europe

What the limit means in practice

2 watts ERP put a ceiling on the range of passive tags. Realistic read distances with retail labels in Europe are therefore around one to twelve metres and no more. In the United States FCC Part 15 permits four watts EIRP, which corresponds to roughly 2.4 watts ERP, so range figures from American datasheets and videos cannot be carried over unchecked to a European shop. Devices sold for those other regions work on 902 to 928 MHz; they are hardware variants, they may not be operated in Europe, and the EU variant has to be ordered explicitly.

One harmonised band, national regulators

Because the band is harmonised, the same device is legal in every EU and EEA country; what differs is the national regulator that administers the general authorisation — the Bundesnetzagentur in Germany, ARCEP in France, UKE in Poland, RDI in the Netherlands, and so on. Many devices are built as worldwide-band versions for 860 to 960 MHz and set to the local rules through a region profile, so when buying abroad or through a marketplace, check that the device is set to the EU region and that an EU declaration of conformity exists. The United Kingdom sits outside this framework: since leaving the EU it applies its own rules, with Ofcom interface requirement IR 2030 and UKCA marking in place of CE.

Other rules that apply

• ISO/IEC 18000-63, or EPC Gen2 v2: the air interface protocol.
• Directive 2014/53/EU (RED): market access for radio equipment, CE marking.
• GDPR: relevant only once tag numbers are linked to personal data.
• Occupational safety: the permitted limits for electromagnetic fields are comfortably undercut by a 2-watt reader in normal retail use.

What matters when a small shop chooses

Battery life

What matters is whether a complete counting run gets through without a charging break. Depending on the device and the transmit power, run times under continuous reading lie between about four and ten hours. More important than the number on the datasheet is whether the battery can be swapped. A spare battery costs little and takes every risk out of the counting day.

Weight

Walk the floor for two hours with an outstretched arm and you feel every gram. Compact terminals weigh around 200 to 350 grams, pistol-grip devices 500 to 800 grams. The grip shifts the load more favourably, though, so a heavier device with a grip can be more comfortable over time than a lighter one without. Trying beats the datasheet.

Ruggedness

Two values count: the drop height in metres onto concrete, and the IP rating against dust and water. Retail devices are usually built for drop heights of around one and a half metres and protected to IP54 or IP65. For a fashion shop that is ample; a consumer smartphone in a sled is not, once it lands on tiles without a case.

Operability by temporary staff

The underrated criterion. A device that only the owner can operate becomes a bottleneck. What is good is what counts in three steps: switch on, start the count, hold the trigger. Anything that needs menu training costs time on every counting day. Large buttons, a clear progress bar and an error list in plain words rather than codes all help.

The software link

The reader delivers numbers. Whether those become usable stock is down to the software. Points to check: the import of article master data from the till system, the marrying of barcode and RFID number during labelling, the comparison of book stock against counted stock, the export as CSV or Excel back into the till system, and whether the device keeps counting offline when the Wi-Fi in the stockroom drops out. A cheap reader with a poor link is dearer than an expensive one with a good link.

Handheld or fixed installation

When a handheld is enough

• One sales floor, one stockroom, one team.
• A stocktake one to four times a year, plus regular partial counts.
• Incoming goods are opened and checked by hand anyway.
• New collections are labelled in the shop.
• An item in stock has to be found quickly — the search function with an audible signal is a handheld discipline that no fixed installation replaces.

When a fixed installation pays off

• Goods out have to be documented automatically and without gaps, when shipping from the shop for instance.
• Theft detection is to run without a separate EAS system.
• Several locations exchange goods and need automatic booking in and out.
• Goods-in covers so many boxes that a tunnel reader saves noticeable staff time.

The typical mistake

Small retailers are occasionally offered a gate, because it sounds like completeness. But a gate gives only an event on a line, not a picture of stock. Without a clean opening stock there is little to be gained from it. The order is the other way round: first build a well-kept stock with a handheld, then check whether a fixed reader still adds anything.

Combining the two as a next step

In practice a two-step approach often emerges: a handheld handles stocktaking, goods-in, labelling and search; later a single fixed reader with two antennas is added at the stockroom door, once a web shop is being fed with live stock levels and every removal has to be visible at once. That order keeps the initial investment small and still gives a clear path for expansion.

Common questions about RFID readers

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