What is RFID?
A chip, an antenna, a number — and the ability to record thousands of items in seconds without looking at any of them. This guide explains the technology from the ground up and gives the figures that count in practice.
RFID stands for radio-frequency identification. A small chip with an antenna — called a transponder or tag — stores an identification number and sends it by radio to a reader as soon as it enters the reader's field. Unlike a barcode, RFID needs no line of sight: a reader records hundreds of tags in fractions of a second, through boxes and through stacks.
- How RFID works
- The three parts of an RFID system
- Frequency bands and read ranges
- Passive, semi-passive, active
- Standards: EPC Gen2, ISO and the legal framework
- RFID compared with the barcode
- RFID and NFC
- What RFID costs
- Where RFID is used
- Limits and sources of error
- Data protection
- RFID in fashion retail
How RFID works
The reader builds up an electromagnetic field. A passive tag has no battery; it draws its energy from exactly that field. As soon as the chip has power it changes how the field is reflected back and returns its number that way — a method called backscatter. An anti-collision protocol arranges for many tags to answer one after another instead of drowning each other out.
The whole exchange takes a fraction of a second. Because the field does not have to be aimed like a laser beam, it makes no difference whether the label faces forward, sits in a hem or lies under three other garments. That is the difference that makes RFID interesting in retail.
A modern UHF reader records several hundred tags a second in practice. The limiting factor is therefore rarely the technology but the pace at which a person walks through the room.
The three parts of an RFID system
Every RFID system has three parts: the transponder on the item, the reader with its antenna, and software that turns the numbers it reads into usable information. Without the software you are left with a list of numbers that means nothing.
1. The transponder (tag)
A microchip with a printed or etched antenna on a carrier material. That unit is called an inlay, and depending on the format it sits in a paper label, a swing tag, a plastic housing or sewn into a hem. The chip normally stores a globally unique number to the EPC standard. More on RFID tags and formats →
2. The reader
It creates the field, addresses the tags and takes in their replies. There are handhelds, fixed readers at doorways and on shelves, tunnel readers for goods-in and desktop units for labelling. More on RFID readers →
3. The antenna
It determines where the field radiates and how far. Polarisation, gain and beam width decide whether a tag is read in any orientation at all or only when it happens to hang the right way. More on RFID antennas and read range →
Frequency bands and read ranges
RFID works in three frequency ranges. LF at 125 to 134 kHz reaches a few centimetres and is markedly less sensitive to metal and liquids than the higher bands, though not wholly unaffected by them. HF at 13.56 MHz reaches about one metre and is the basis of NFC. UHF at 865 to 868 MHz in Europe reaches several metres and is the standard in retail and logistics, because it is the only band that allows bulk reading over several metres.
| Band | Frequency | Read range | Typical use | Retail? |
|---|---|---|---|---|
| LF | 125–134 kHz | up to ~10 cm | Animal identification, access control, immobilisers | no |
| HF | 13.56 MHz | up to ~1 m | NFC, libraries, ID cards, payment cards | rarely |
| UHF | 865–868 MHz (EU) | 1–12 m | Retail, logistics, stocktaking, article surveillance | yes |
| UHF | 902–928 MHz (North America) | 1–15 m | same uses, different band | yes |
Because Europe and North America use different UHF bands, readers are not always interchangeable worldwide. Modern tags usually cover both ranges, whereas readers are often configured for one region. A device sold for 902 to 928 MHz is a hardware variant for North America and may not be operated in Europe, so order the EU variant explicitly.
Passive, semi-passive, active
Passive tags have no battery, cost a few cents and go on working for practically unlimited time — they are the standard in retail. Semi-passive tags carry a battery for the electronics but still reply by backscatter. Active tags transmit on their own and reach up to a hundred metres, but they cost many times as much and last only as long as their battery.
| Type | Power | Read range | Price per unit | Service life |
|---|---|---|---|---|
| Passive | from the reader's field | up to ~12 m | approx. €0.05–0.30 | practically unlimited |
| Semi-passive | battery for the chip, backscatter to reply | up to ~100 m | several euro | battery life |
| Active | own battery, transmits itself | up to ~500 m | tens of euro upwards | battery life |
For clothing, footwear and sports goods only passive UHF tags come into question. Anything else would be unaffordable and technically over-specified.
Standards and the legal framework
The governing standard in retail is EPC Gen2, standardised as ISO/IEC 18000-63. It sets out how tags and readers talk to each other and how the numbers are structured. For radio operation the rules are harmonised across the EU and the EEA through CEPT recommendation ERC/REC 70-03 and the harmonised standard ETSI EN 302 208: the 865 to 868 MHz band, at most 2 watts ERP. Operating inside that general authorisation needs no individual licence, no registration and no spectrum fee. What differs from country to country is only the regulator that administers it — Bundesnetzagentur in Germany, ARCEP in France, UKE in Poland, RDI in the Netherlands, and so on. The United Kingdom is outside this framework: since leaving the EU it applies its own rules under Ofcom IR 2030, with UKCA marking instead of CE.
The chip normally holds a number in the EPC scheme, in retail usually an SGTIN-96 — the GTIN article number plus a running serial number. That identifies not only the article type but every single piece. This is exactly what the stock accuracy RFID gains over the barcode rests on.
In addition every chip carries an unchangeable identifier, the TID. It names the manufacturer and the chip model and cannot be overwritten. Many chip types extend it with a globally unique serial number — with those, two labels can be told apart even when they carry the same EPC number.
RFID compared with the barcode
A barcode has to be seen, an RFID tag does not. That is why a barcode scanner records one item per movement of the hand while a UHF reader records hundreds a second. The barcode identifies the article type; the RFID tag identifies the individual piece as well. In return a barcode costs nothing and an RFID label around 12 to 15 cents.
| Barcode | RFID (UHF) | |
|---|---|---|
| Line of sight needed | yes | no |
| Reading | one at a time | hundreds at once |
| Identifies | article type | individual piece |
| Cost per label | effectively €0 | approx. €0.12–0.15 |
| Readable through cardboard | no | yes |
| Writable | no | yes |
| Affected by metal | no | yes |
In practice RFID rarely replaces the barcode. The two run side by side: the barcode stays the basis for the till and for suppliers, and the RFID tag is added on top for stock control.
RFID and NFC
Technically NFC is a special form of RFID in the HF band at 13.56 MHz. The range is a few centimetres and communication runs between exactly two devices. That is ideal for contactless payment and useless for a stocktake — for that you need UHF RFID with bulk reading over several metres.
The commonest misunderstanding in practice: because almost every smartphone handles NFC, it looks as though you could count stock with one. You cannot. A smartphone reads an NFC tag from a few centimetres away, one after another — that is no faster than a barcode scanner.
What RFID costs
A passive UHF label costs around 12 to 15 cents in small quantities; buyers ordering in bulk pay under 5 cents. An RFID handheld runs from about 500 to 3,000 euro net depending on specification, an RFID printer from 1,300 to 1,700 euro net. Software comes on top of that.
- UHF label, small quantity
- approx. €0.12–0.15 per unit
- UHF label, bulk purchase
- under €0.05 per unit
- Entry-level handheld
- from approx. €500
- Rugged handheld with pistol grip
- approx. €1,200–3,000
- RFID printer (print & encode)
- approx. €1,300–1,700
- Software
- subscription or project price, varies widely by supplier
List prices as quoted by German specialist dealers. Daily prices and discounts differ. All figures are net and exclude VAT; business buyers elsewhere in the EU holding a valid VAT identification number are invoiced under the reverse-charge procedure.
Where RFID is used
RFID sits today in access badges, ski passes, library books, laundries, car keys, animal chips, passports, toll systems and pallets in logistics. The largest commercial field of use is clothing retail, where individual garments are recorded piece by piece.
- Fashion retail — stocktaking, stock accuracy, article surveillance, availability for the web shop. The field with the greatest benefit per label.
- Logistics — goods-in without unpacking, pallet and container tracking, loading checks.
- Laundry and hospitality — washable tags in textiles that survive hundreds of wash cycles.
- Libraries — self-issue and return machines, mostly in the HF band.
- Industry — tool and equipment management, asset stocktaking.
- Access and ticketing — staff badges, ski passes, event wristbands.
Where RFID reaches its limits
Metal reflects the field, liquids absorb it — either one cuts the read range sharply or prevents a read altogether. Special on-metal tags exist for that, but they are thicker and dearer. The orientation of the tag, dense stacking and the human body also affect the result.
- Metal and liquids. In textiles this hardly matters; with cosmetics, drinks or tools it does.
- Over-reading. A device set too strong also reads stock in the next room. That produces stock levels which do not exist on the shop floor at all.
- Shadowing. Very tightly packed goods in the middle of a large stack are occasionally missed.
- Faulty tags. A small percentage of labels is unreadable out of the factory or after mechanical stress. That is why good printers verify every label after encoding it.
What is on an RFID tag
A commercial RFID label holds a number and nothing else — no customer data, no name, no date of purchase. The tag has no power source of its own and can only be read when a reader is within range. In retail it is normal practice to remove or deactivate the label at the point of sale.
The worry about tracking assumes that someone runs readers across a whole area and can link the number to a person. Neither is the case in ordinary retail. Even so, the use of RFID belongs in your privacy notice as soon as tags can leave the shop; the GDPR applies throughout the EU and the EEA.
RFID in fashion retail
In clothing retail, stock accuracy without RFID is typically 65 to 75 per cent, and with RFID 93 to 99 per cent. A full stocktake that takes a weekend by hand is done with a handheld in one to two hours. These figures come from a 2018 study of ten retail businesses carried out for the ECR Shrinkage & OSA Group and GS1 UK.
The practical procedure is easy to follow: every article gets an RFID label in addition to its barcode, and that label is linked to the barcode once. After that a single walk round with the handheld records the whole stock — including what is sitting in a box in the cellar.
Large chains have worked this way for more than ten years. For independent shops the technology was long too dear and too complicated, because it had to be integrated into a merchandise management system. That is exactly where HANGCOUNT comes in: the RFID label is married to the existing barcode, the till system is left untouched, and the counted figures come back as CSV or Excel.
Want to tag your own stock?
HANGCOUNT provides RFID stock control for fashion shops, boutiques and sports retailers: software from 99 euro per month per location, plus 2,900 euro once for the hardware. Labels are charged as used. All prices net. Send us your rough number of pieces and we will work out how long your stocktake would take — and say plainly if it does not pay for you.
Common questions about RFID
What does the abbreviation RFID stand for?
RFID stands for radio-frequency identification: identifying things by means of electromagnetic waves. A small chip with an antenna — the transponder, or tag — sends a stored number to a reader on request. Unlike a barcode, no line of sight is needed.
How does RFID work technically?
The reader emits an electromagnetic field. Passive tags have no power source of their own; they draw their energy from that field. As soon as the chip has enough energy it modulates the field and sends its identification number back. This method is called backscatter. An anti-collision procedure makes sure that hundreds of tags are read in one pass without interfering with each other — they answer in separate time slots.
How far does RFID reach?
That depends on the frequency band. LF at 125 kHz reaches a few centimetres, HF at 13.56 MHz about one metre, UHF at 865 to 868 MHz in Europe several metres. In practice the range is limited by metal, liquids, the orientation of the tag and the permitted transmit power.
What does an RFID tag cost?
A passive UHF label costs about 12 to 15 cents each in small quantities. Large buyers ordering in the millions pay less than 5 cents. The price depends on the format, the chip type and the order quantity, not on the read range. All prices are net and exclude VAT.
What is the difference between RFID and NFC?
NFC is a special form of RFID in the HF band at 13.56 MHz with a range of a few centimetres. It is built for communication between exactly two devices, a smartphone and a payment terminal for instance. UHF RFID by contrast records hundreds of tags in one pass over several metres — that is the only way a stocktake on the move works.
Can RFID track people?
A passive retail tag contains nothing but a number, no personal data, and it has no power source of its own. It can only be read when a reader is within range. Tracking outside the shop would require readers installed right across an area. In retail it is normal practice to remove or deactivate the tag at the point of sale.
Does RFID need a licence?
No. Operating in the European UHF band from 865 to 868 MHz needs no licence and no registration as long as the harmonised standard ETSI EN 302 208 is met. The maximum transmit power is 2 watts ERP. Commercial readers and labels meet these limits as supplied. The band is harmonised across the EU and the EEA; the United Kingdom applies its own rules under Ofcom IR 2030.
Does RFID replace the barcode?
Mostly not, in practice. The barcode usually stays and is supplemented by the RFID label, because till systems, suppliers and processes are built on it. The barcode identifies the article type; the RFID tag identifies the individual piece as well.