100PCS CUID Gen2 UID Changeable NFC IC Cards | MCT Android

100-Pack CUID Gen2 UID-Changeable NFC IC Cards

Upgrade your NFC projects with this bulk pack of 100 CUID Gen2 UID-Changeable IC Cards. Compatible with the popular MCT (Mifare Classic Tool) Android app, these CR80-sized cards let you freely read, write, and modify the 4-byte UID directly from your NFC-enabled Android smartphone — no specialist hardware required.

Key Features

• Fully Changeable UID: 4-byte UID can be rewritten repeatedly, making these ideal for testing, development, and access-control prototyping.
• Gen2 CUID Chip: Fully compatible with Mifare Classic 1K readers and systems for seamless integration.
• Android App Support: Modify the UID wirelessly using the free "MCT" app (search "MCT" in the Google Play Store). Requires an NFC-enabled Android device with NFC turned on.
• 1K Memory: 1,024 bytes of usable storage organized in 16 sectors, standard Mifare Classic 1K layout.
• Fast Read/Write: Communication rate of 106 Kbaud with read/write response time of just 1–2 ms.
• Standard CR80 Card Size: Identical in size to a credit card — fits any standard card holder, wallet slot, or badge clip.
• Long Service Life: Flash write endurance exceeding 100,000 cycles with data retention of over 10 years.
• Wide Operating Range: Works reliably from −20°C to +85°C; read/write distance 0–10 cm (varies by reader).
• Bulk Value Pack: 100 cards per order — perfect for large deployments, R&D labs, and maker projects.

Technical Specifications

How to Use

1. Ensure your Android phone has NFC capability and that NFC is enabled in your settings.
2. Download the free MCT (Mifare Classic Tool) app from the Google Play Store.
3. Place the CUID card against your phone's NFC antenna.
4. Use MCT to read, write, or change the UID as needed for your project.

Note: UID software changes apply to CUID cards. Changing the UID of a standard keyfob via software is a different process — please confirm your card type before writing.

Who Is This For?

These cards are popular with electronics hobbyists, IoT developers, security researchers, and system integrators who need a convenient, reprogrammable NFC card for prototyping access-control systems, smart home triggers, inventory tagging, or NFC automation workflows.

For background on NFC and RFID standards, visit the NIST Guidelines on Securing RFID Systems.

Frequently Asked Questions

Q: What Android app do I need to change the UID on these CUID NFC cards?

A: Search for "MCT" (Mifare Classic Tool) in the Google Play Store and install it for free. Your Android device must have NFC hardware and NFC must be switched on before the app can communicate with the card.

Q: Are these CUID Gen2 cards compatible with standard Mifare Classic 1K readers?

A: Yes. The CUID Gen2 chip is fully compatible with Mifare Classic 1K readers and systems, making these cards a drop-in option for most 13.56 MHz NFC access-control and data-capture setups.

Q: How many times can I rewrite the UID on each card?

A: Each card supports more than 100,000 write cycles, so you can change the UID repeatedly throughout development and testing without worrying about card wear.

Q: Do these cards work with iOS (iPhone)?

A: These cards are designed for use with NFC-enabled Android devices running the MCT app. iOS support is limited due to Apple's NFC API restrictions; Android is strongly recommended for UID modification.

Q: What is the read/write range of these NFC IC cards?

A: The operating distance is 0–10 cm, though the actual range depends on your specific card reader or smartphone NFC antenna strength.