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Start with the existing reader and required transaction
A reader displaying a UID proves identification, not authentication, protected-data access or enrollment. Ask the system owner what the credential must actually do.
- Record the reader model, firmware, host software, supported commands and credential encoder.
- Specify the application, data format and authorization process. A hotel-lock brand or “13.56 MHz” is insufficient.
- Use a non-production sample to demonstrate the complete transaction, including rejection of an unauthorized credential.
Which chip family fits your buying question?
| Required outcome | Families to investigate | Evidence to request |
|---|---|---|
| Existing access credential | The supported LF or MIFARE configuration | Enrollment and transaction test |
| Public phone link | NTAG213 / 215 / 216 | NDEF payload on target phones |
| Phone-based tag authentication | NTAG 424 DNA | Provisioning and server verification |
| Bulk item identification | Impinj M700 / M800 series; NXP UCODE | Finished inlay and item-level read test |
| Authenticated card applications | MIFARE Plus EV2 or DESFire EV3 | Supported mode, keys and commands |
MIFARE Classic, Plus EV2 or DESFire EV3?
MIFARE is a family name, not a universal compatibility statement. NXP does not recommend Classic EV1 for new designs. Existing systems need a documented migration decision.
NXP lists Common Criteria EAL5+ for DESFire EV3 hardware and software. This IC certification does not certify the supplied card, payment service or complete installation. Obtain the exact certificate scope required by your project.
| Chip | Memory and organization | Buyer decision |
|---|---|---|
| Classic EV1 | 1 KB / 4 KB, sectors and blocks | Check the installed legacy application and replacement plan. |
| Plus EV2 | 2 KB / 4 KB, sector structure | Define SL1, SL3 or mixed operation. AES-128 in SL3 requires reader and application support. |
| DESFire EV3 | 2 / 4 / 8 / 16 KB, applications and files | Size files, access rights and keys; reserve application overhead. |
NTAG213, 215 and 216: size the actual NDEF message
NTAG213, NTAG215 and NTAG216 provide 144, 504 and 888 bytes of user memory respectively. NDEF headers and formatting consume space: test the encoded message, not only its visible character count.
Apple documents background reading on iPhone XS and later, subject to device state and a supported NDEF URI. Android MIFARE Classic support is optional. Test the phones, operating systems and tag placement; “NFC-enabled” alone is insufficient.
- For a website, use a stable HTTPS URL and confirm the complete encoded record fits.
- For offline contacts or multiple records, test a realistic payload in the intended phone app.
- Password protection and locking are available, but these chips do not provide AES message authentication. A locked URL can still be copied.
NTAG 424 DNA needs a working verification service
NTAG 424 DNA supports AES-128 and Secure Unique NFC messages through Secure Dynamic Messaging. Its 416-byte file space comprises a 32-byte capability file, 256-byte NDEF file and 128-byte data file; it is not a 416-byte URL store.
Agree who provisions keys, configures tags and operates the verifier. The server must validate messages and handle replay risks. NXP describes residual risks from captured messages; a changing URL alone does not prove a fresh tap.
Product authenticity also depends on binding the tag to the correct item. A read counter does not establish that packaging was opened or a customer used the product. Define tamper detection separately.
Impinj and UCODE: separate EPC, TID and user memory
EPC memory normally holds the item identifier; TID identifies the IC according to its implemented memory map; user memory stores additional data where available. Specify lengths in bits. EPC or TID reads alone are not cryptographic authentication.
M800 names a series, not one memory layout. Extended memory does not make an inlay suitable for metal. Compare the complete antenna and tag on your object with the intended regional reader setup. UCODE DNA supports AES authentication, requiring compatible commands and key management.
| IC or configuration | EPC bits | User bits |
|---|---|---|
| Impinj M730 / M830 | 128 | 0 |
| Impinj M750 / M850 | 96 | 32 |
| NXP UCODE 9 | 96 | 0 |
| NXP UCODE 9xm | 128 / 256 / 496 | 752 / 624 / 384, respectively |
LF replacements require an exact format match
Match frequency, modulation, data rate and identifier format before ordering an LF replacement. A programmable chip is not automatically compatible with every access reader.
EM4205/EM4305 provides 512 bits of EEPROM in 16 words of 32 bits, including configuration and reserved functions. This is not 512 freely usable application bits. Its documented operating range is 100–150 kHz; verify the finished tag’s configured protocol and enrollment.
Prove a replacement before changing the order
Shared standards and backward-compatibility features do not guarantee operation without software changes. Require approval for substitutions and repeat affected tests.
- Document the old credential, commands, memory, key handling and issuance process with the system owner.
- Test the proposed finished credential on representative readers, including mixed old/new operation.
- For Plus, verify the security level; for DESFire, verify applications and authentication, not just detection.
- Approve rollout and recovery procedures before switching keys, locking memory or changing live credentials.
Approve the chip and the finished product separately
Request traceable part identification and agreed lot records. Use the manufacturer’s supported originality procedure where available; a familiar UID prefix alone is not proof of origin.
- Check memory, access rights, encoding and duplicate handling against the approved sample.
- Measure transaction success on the actual object, at the required position and orientation.
- For laundry, outdoor or metal-mounted tags, request evidence for that construction and exposure profile.
- Agree sample quantity, pass criteria, inspection records and treatment of failures before production.
Compare quotations for the same finished configuration
Chip-only, inlay, printed-card and encoded-label prices cover different scopes. Request an itemized finished-product quotation.
- Fix the chip part, memory, antenna, size, material, printing and attachment.
- Separate encoding, secure provisioning, tooling, samples and testing from unit price.
- State quantity per configuration, reorder forecast, destination and required date.
- Confirm MOQ, supply status, quote validity and lead time for that specification.
Common decisions
Questions buyers ask before choosing
Which RFID chip is best for my product?
Select the chip that completes your required transaction on the intended reader. Start with compatibility, data and authentication, then validate the proposed finished card or tag.
Does a DESFire-compatible reader guarantee a working card?
No. Confirm generation, commands, application files, key handling and host integration. Reading a UID is a different test from completing a protected transaction.
How much memory do NTAG213, NTAG215 and NTAG216 have?
Their user-memory capacities are 144, 504 and 888 bytes. NDEF formatting consumes space, so encode and test the actual payload before selecting a variant.
Will every NFC phone read my card or label?
Test tag technology, NDEF content, phone model, operating system and placement. Apple background reading has device-state conditions; Android MIFARE Classic support is optional.
Does NTAG 424 DNA prevent all cloning or replay?
No. Cryptographic messaging requires correct configuration, protected keys and a verifier that handles replay risks. It does not prove the physical item carrying the tag is genuine.
Can UCODE 9 store an item’s full history?
Standard UCODE 9 has 96-bit EPC memory and no user memory. Store history in linked software records, or specify a documented extended-memory part for local storage.
Can I substitute an Impinj chip for a UCODE chip?
Treat it as a controlled change. Compare commands, memory layout, encoding and locking behavior, then test the finished inlay on the reader and tagged object.
Does choosing a chip establish read range or wash life?
No. Antenna, construction, mounting, environment and reader setup affect performance. Agree a measurable finished-product test.
What is needed for a chip-based quotation?
Send the transaction, reader, chip or alternatives, data format, finished specification, quantity and destination. Define sample acceptance requirements; keep live authentication keys out of the inquiry.
Move from the guide to a sample
Product options to investigate
These pages describe product formats. Confirm the exact chip, construction and system compatibility for your selected configuration.
Custom PVC RFID Card
Compare blank, printed and encoded PVC RFID cards by chip, artwork, dimensions and issuer workflow. Review a representative sample before bulk ordering.
Custom NFC Sticker
Choose custom NFC stickers by NDEF content, chip memory and mounting surface. Approve artwork and encoded samples on the target phones before production.
Custom UHF RFID Sticker
Select UHF RFID stickers by item, finished inlay and reader setup. Confirm EPC data, printing and roll format, then validate mounted samples.
RFID Keyfob
Compare RFID keyfob housings after confirming the reader and credential format. Plan authorized samples, numbering and repeat orders for access programs.
RFID Card Inlay
Specify RFID card inlays by chip, antenna, sheet layout and card stack. Compare LF, HF, UHF and multi-chip builds before a lamination trial.
RFID Reader Writer
Choose an RFID reader writer by card protocol, read/write task and host software. Compare USB, network and OEM hardware before requesting an evaluation.
Check the basis for your decision
Sources and technical references
Chip and standards references describe their own scope. They do not establish a finished product’s read distance, durability or compatibility.
- NXP: MIFARE Classic EV1
Legacy positioning and recommendation for new designs.
- NXP: MIFARE Plus EV2
Memory, security levels and AES operation.
- NXP: MIFARE DESFire EV3
Memory variants, file architecture and IC certification.
- NXP: NTAG213/215/216
User memory, NDEF mapping and access controls.
- NXP: NTAG 424 DNA
Memory organization and SDM limitations in section 9.3.
- Impinj: M730 and M750
EPC and user-memory configurations.
- Impinj: M830 and M850
M800 model names and memory configurations.
- NXP: UCODE family comparison
UCODE 9 memory and UCODE DNA AES support.
- NXP: UCODE 9xm
Paired EPC/user-memory configurations in section 9.5.
- EM Microelectronic: EM4205/4305
LF range, EEPROM organization and configuration.
- Apple: Background tag reading
Supported phones, NDEF URI handling and restrictions.
- Android: MIFARE Classic support
MIFARE Classic support is optional on Android NFC devices.