Yes: EPC Class 1 Gen 2, ISO/IEC 18000-63 and RAIN RFID are three names for one passive UHF air interface. In a specification, cite the GS1 Gen2 release and a dated ISO/IEC edition, and use “RAIN” only as a description.
Short answer: one protocol, three bodies behind the names. Cite the GS1 release and the dated ISO/IEC 18000-63 edition current at tender date (2021 as of October 2026); Gen2v3 features are defined in the GS1 release. Never treat “RAIN” as a compliance mark.
| Term | Who defines it | What it is | What to write |
|---|---|---|---|
| EPC Class 1 Gen 2 (EPC Gen2) | GS1, formerly through EPCglobal | Protocol text: GS1 Gen2 Standard, Release 3.0.1 (Feb 2026), 860–930 MHz, free PDF | ”GS1 EPC Radio-Frequency Identity Generation-2 UHF RFID Standard, Release ___ or later” |
| ISO/IEC 18000-63 | ISO/IEC JTC 1/SC 31 | The same air interface as an international standard: ISO/IEC 18000-63:2021, Edition 3, titled 860–960 MHz, a paid document. Edition 4 is under publication | The dated edition current at tender date: “ISO/IEC 18000-63:2021” as of Oct 2026 |
| RAIN RFID | RAIN Alliance | An industry name for passive UHF RFID that uses ISO/IEC 18000-63. Not a standard; the name is not a trademark (the emblem is the Alliance’s mark); the Alliance does no compliance testing | Descriptive only: “passive UHF (RAIN RFID)”. Never “RAIN-approved” |
None of the three applies to HF (13.56 MHz), NFC, LF (125 kHz or 134.2 kHz) or BLE (2.4 GHz).
Who defines each name, and why are there three?
GS1 set up EPCglobal in 2003, and EPCglobal first published Gen2 in 2004 (GS1 Gen2 page; GS1 Gen2v3 fact sheet). The change log in Release 3.0.1 records two harmonisations with ISO: version 1.1.0 (December 2005) with the ISO 18000-6 Type C amendment, and version 2.1.0 (July 2018) with ISO/IEC 18000-63.
The “Class 1” wording is history. Version 1.2.0 of 2008 was titled “Class-1 Generation-2 UHF RFID Protocol”; the word is absent from the titles of v2.0.1 (April 2015), 2.1 and 3.0.1. GS1’s own Tag Data Standard 2.3 treats UHF Class 1 Gen 2 tags and ISO/IEC 18000-63 tags as the same thing.
RAIN came later. The RAIN Alliance was founded in April 2014 by Google, Intel, Impinj, Smartrac and AIM. It defines RAIN as passive UHF RFID on the ISO/IEC 18000-63 air interface, says the name derives from RAdio IdentificatioN and is not a registered trademark, and records an agreement with GS1: the technology is called RAIN and GS1’s data system is the EPC. The Alliance draws the analogy itself: NFC names a passive HF standard, RAIN names passive UHF.
So three bodies do three jobs. GS1 writes the protocol and gives it away. ISO publishes it as an international standard that a public tender can cite. The Alliance promotes the technology. Our RFID glossary lists related terms.
How did ISO 18000-6 Type C become ISO/IEC 18000-63?
ISO 18000-6C is an old label for a current technology. ISO added Type C to ISO/IEC 18000-6:2004 through Amendment 1 of 2006, and in 2013 Type C moved to its own part, ISO/IEC 18000-63:2013. GS1’s support note puts it plainly: 18000-63 is the new name for the former 18000-6 Type C.
The ISO/IEC 18000-63 editions, as ISO’s catalogue listed them on 25 October 2026:
- Edition 1 (2013) and Edition 2 (2015): withdrawn.
- Edition 3 (2021): current, published November 2021, and marked for revision since June 2023.
- Edition 4: under publication since 26 August 2026 and due to replace the 2021 text. The catalogue does not say whether it carries the Gen2v3 changes.
Type B is not Gen2. It is ISO/IEC 18000-62:2012, a separate protocol, confirmed in 2023. If a datasheet still says 18000-6C, read it as 18000-63 and ask which edition or GS1 release the supplier means.
Is it 860–960 MHz or 860–930 MHz, and what does India use?
Both figures are in circulation. GS1 Release 2.1.0 and ISO/IEC 18000-63:2021: 860–960 MHz. GS1 Release 3.0 onward and the RAIN Alliance’s brand guidelines: 860–930 MHz.
Neither range is a licence. Gen2’s own frequency table leaves the operating band to local regulations. India’s licence-exempt UHF RFID band is 865–868 MHz under G.S.R. 853(E) of 10 December 2021, which superseded the 2005 rules. Readers may transmit 2 W e.r.p. only in four channels centred at 865.7, 866.3, 866.9 and 867.5 MHz, with EN 302 208 as the reference. A chip datasheet span such as 840–960 MHz is a tuning range, not permission to transmit. For imported hardware, see whether a US 902–928 MHz reader can be used in India.
Who tests Gen2 conformance, if the RAIN Alliance does not?
Not the RAIN Alliance. The Alliance’s FAQ says it does not test for compliance; a compliant tag or reader is simply one that follows ISO/IEC 18000-63 and the relevant data-encoding rules. Its brand guidelines list “RAIN-approved” as incorrect usage and give as correct usage wording that names ISO/IEC 18000-63. The Alliance’s paid encoding masterclass exam certifies individuals, not products.
GS1 publishes the Gen2 conformance requirements. Its Conformance Requirements, Release 3.0.1 bar a device from claiming conformance unless it meets every non-optional clause and all local radio regulations. GS1 says it is proposing a certification programme and keeps a list of certified devices, each tested by a GS1-accredited laboratory.
In India, WPC and BIS approvals are issued for radio equipment such as readers, not for a protocol name, and passive tags need neither because they have no transmitter. Ask for the conformance claim in writing, against a named GS1 release.
Why do HF, NFC, LF and BLE fall outside Gen2?
Because EPC Gen2, ISO/IEC 18000-63 and RAIN are passive UHF only. HF works at 13.56 MHz under ISO/IEC 14443 or ISO/IEC 15693, and NFC is HF. LF cards and fobs use 125 kHz, and animal ID uses 134.2 kHz FDX-B under ISO 11784/11785. BLE is a battery-powered 2.4 GHz radio, not passive RFID.
One source of confusion is GS1’s separate EPC Class-1 HF RFID Air Interface Protocol, v2.0.3 (September 2011): a 13.56 MHz protocol whose ASK signalling is backwards compatible with ISO 15693, with an optional PJM mode, and a different air interface from UHF Gen2. An “EPC” or “Class-1” label on an HF item does not make it Gen2, so a tender must name the HF standard itself. A UHF reader reads neither HF nor LF, and a phone’s NFC never reads UHF. Our UHF vs HF vs NFC comparison covers the choice, and whether a 13.56 MHz NFC reader needs WPC approval covers the paperwork.
Which GS1 release and ISO edition should a tender cite?
Name releases, not nicknames. Gen2v2 is Release 2.0.0 (October 2013); Gen2v3 is Release 3.0; the current text is Release 3.0.1, ratified February 2026.
Dates matter on the ISO side too. Release 3.0.1 sets the rule for its own normative references: a dated reference means only the edition cited, while an undated one means the latest edition with amendments. “ISO/IEC 18000-63:2021” fixes the text; “ISO/IEC 18000-63” alone moves to Edition 4 once it is published.
On revisions, GS1 says Gen2v3 deprecates nothing and includes every Gen2v2 feature, and its fact sheet says Gen2v3 is backward compatible, so Gen2v2 deployments keep working. The same fact sheet says chip and reader makers must update their products to comply. Require Release 3.0 or later only for features you can name. What the revisions change, release dates included, and where Impinj’s Gen2X fits, is in our Gen2X and Gen2v3 guide; for the reader side of the revisions, see identiumone’s RAIN reader guide.
What should the specification clause say?
A specimen clause to adapt:
Air interface. Passive UHF RFID to the GS1 EPC Radio-Frequency Identity Generation-2 UHF RFID Standard, Release ___ or later, and ISO/IEC 18000-63:2021 (formerly ISO/IEC 18000-6 Type C), or the later edition the bidder declares.
Optional Gen2 features required. None / [list each feature by name and clause].
Gen2v3 features. Where Release 3.0 or later is specified, the features required shall be listed by name; ISO/IEC 18000-63:2021 predates Release 3.0.
Band. Readers shall operate in India’s licence-exempt 865–868 MHz band under G.S.R. 853(E) of 10 December 2021.
Declaration. The bidder shall state in writing the GS1 release and ISO/IEC edition claimed for each tag and reader offered.
Terminology. “RAIN RFID” is descriptive and is not accepted as evidence of compliance.
Other frequencies. HF, NFC, LF or BLE items shall be separate lines, each naming its own standard.
ISO/IEC 18000-63:2021 was published in November 2021, before GS1 ratified Gen2v3 (Release 3.0, January 2024), so features added in Release 3.0 are specified only in the GS1 text until a later ISO edition is confirmed to include them. If you require them, name them against the GS1 release and do not assume the ISO edition carries them. Use the ISO edition current at tender date, and check the year again once Edition 4 is published.
The rest of the bill of quantities, from read-rate acceptance to encoder lines, is in our tender and BOQ specification guide.
How do EPC, Gen2 and EPCIS fit together?
EPC is the identifier. GS1’s Tag Data Standard 2.3 (ratified October 2025) defines the Electronic Product Code and the memory contents of Gen2 tags, so the EPC is what you write into the tag’s EPC memory; Gen2 is how the reader talks to the tag. EPCIS 2.0 (ratified June 2022) is a standard for sharing supply-chain event data. It needs neither EPCs nor RFID, and GS1 calls the EPC in its name “of historical significance only”. For encoding schemes, see our EPC TDS 2.3 guide.
Where Identium fits
Identium is a BIS and WPC approved RFID manufacturer in New Delhi. We design and manufacture UHF, HF and LF tags, labels, inlays and cards, and UHF and HF readers, at East of Kailash. Our UHF tags, UHF labels and inlays are passive and use EPC Gen2 (ISO/IEC 18000-63) chips, and our UHF readers read and write them; ask us for the chip and GS1 release in writing. Our HF and NFC tags are separate ISO/IEC 14443 and ISO/IEC 15693 products.
For any part we quote, ask for the chip maker’s datasheet rather than a protocol badge. Custom tag orders typically turn around in 5–10 days. Send us the specification, including the clause above; tags and readers are quoted against specification.