Writable 125khz RFID Tag Proximity Card for Access Control
What Is a Writable 125kHz RFID Tag?
A writable 125kHz RFID tag (a rewritable proximity card) is a contactless smart card that allows cloned, written, and reprogrammed data. Based on the T5577 chip, this card is ideal for access control, employee attendance, visitor management, and door-entry systems that use low-frequency RFID readers.
Unlike fixed-code cards like EM4100, the T5577 chip enables multiple reuses, offering flexibility in cloning or updating credentials — perfect for security integrators, facility managers, and RFID installers.
Key Features & Benefits
- 125kHz Low Frequency – strong signal, ideal for short-range access control
- Rewritable (T5577 chip) – supports cloning and data reprogramming
- Durable PVC card – same size as a credit card (ISO CR80 standard)
- EM4100 Compatible – works with most 125kHz RFID readers
- Supports OEM branding – custom print, serials, or laser ID
- High security, reusable – use in changing access environments
Writable 125khz RFID Tag Technical Specifications
| Feature | Specification |
| Chip Type | T5577 (rewritable) |
| Frequency | 125 kHz (LF) |
| Memory | 330-bit EEPROM |
| Protocol | ISO11784/85 compatible |
| Read/Write | Yes – programmable via RFID writer |
| Material | PVC or PET |
| Size | 85.5mm × 54mm × 0.8mm (CR80 standard) |
| Read Range | 2–10 cm |
| Colors | White (custom colors available) |
| Operating Temp | -25°C to +70°C |
| Customization | Logo printing, UID encoding, QR/barcode, laser serial |
Common Use Cases
Writable 125kHz RFID tags are used in a variety of security and identification systems:
- Access control for offices and buildings
- Hotel room keys and guest entry cards
- Gym and fitness center memberships
- School and dormitory entrance systems
- Parking lot entry passes
- Employee or contractor time attendance
These rewritable cards are especially useful when access rights change frequently or must be reissued regularly.
Customization & OEM Services
As an experienced RFID manufacturer, JIA RFID offers full customization for this product:
- Full-color printing (front and back)
- Laser serial number or barcode
- UID encoding or password protection
- Embedded data, multi-chip support
- Bulk packaging, sample runs, and MOQ support
Do you need to match your existing brand or integrate into a software system? Our team can help configure and test before delivery.
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Frequently Asked Question
The top questions about radio frequency identification, RFID tags, and RFID readers, and RFID cards.
It’s a programmable proximity card that uses the T5577 chip and can be cloned or rewritten for use with access systems.
Writable cards like T5577 can be reprogrammed, while EM4100 cards have a fixed, unchangeable UID.
Yes, using an RFID copier/writer that supports T5577, you can duplicate an EM4100/compatible card to this rewritable version.
If your system supports 125kHz LF (e.g., EM readers), then yes — it’s compatible.
Absolutely. We support full OEM customization including logos, barcodes, QR codes, and laser marking.
MOQ starts from as low as 100 pcs. Lead time is typically 5–10 business days, depending on customization.
Hot To Customize RFID Tags
Know the customization process about RFID tags
Size & Shape
Send your requirements on size and shapes. Tags are typically designed in simple shapes and sizes to match the internal antenna. However, they can also be customized in various sizes and shapes to best fit the intended application and the asset being tagged. For instance, RFID hang tags can be customized in size, shape, and attachment method to perfectly suit specific applications.
Layout & Chips
In the label format designer, select the layout that matches the type and size of the RFID label you wish to create. Our factory provides a variety of label templates, including RFID-specific options. We also offer a range of RFID chips tailored to meet your specific requirements.
High Customization
Custom tags are designed from the ground up to meet the needs of specific applications, with unique variables for nearly every option listed below. A semi-custom tag typically starts as a standard tag but offers additional customization options, such as custom printing, encoding, or specific backings and attachment methods.
Sample Confirmation
Before proceeding with full-scale production, we offer a sample confirmation process to ensure that the RFID tags meet your exact specifications and application requirements.
Mass Production
Our mass production process for RFID tags is designed to deliver high-quality, reliable products at scale, ensuring that your business has a steady and consistent supply of RFID solutions tailored to your needs. Leveraging state-of-the-art manufacturing facilities and advanced technology, we maintain efficiency and precision throughout the production cycle.
RFID Tags Application
Use customized RFID tags in different industries.
RFID Vehicle Tags
Vehicles with RFID tags enable secure access to gated areas. RFID tags also streamline truck weighing for efficient billing.
Temperature Sensor Tags
RFID temperature sensors, used in industries like steel, send data to alert users of unsafe conditions via RFID readers.
RFID Supply Chain Tags
RFID tags for supply chain visibility track products, showing when a box, pallet, or container moves from one facility to another.
RFID Personnel Tracking
RFID strengthens access security: employee badges for workspace entry, hotel wristbands for pool access.
RFID Pallet Tracking Tags
Our RFID tags are ideal for tracking pallets and containers, offering durable, low-profile solutions for warehouse management.
Custom RFID Tags & Labels
Our factory supplies custom RFID tags and OEM hardware solutions for unique needs when standard RFID products aren't available.
RFID Laundry Tags
Our RFID laundry tags, with a soft rubber casing, are flexible and durable, surviving 200 wash cycles and 60 bars of pressure.
Industrial RFID Tags
We provide rugged industrial RFID tags and readers for demanding applications. Our tags withstand all weather conditions.
Animal RFID Tags
RFID tags track animals and pets using ear tags or injectable ampoules. Ear tags can be custom-printed and come in various colors.
RFID Asset Tracking
RFID tags for asset tracking, like file servers, rental equipment, streamline inventory, asset management, enabling quick location, tracking.
Consumables RFID Tags
RFID counterfeit tags on consumables, with a reader in the machine, verify authenticity and prevent counterfeit use.
Manufacturing RFID Systems
RFID tags are used on almost all products—apparel, furniture, appliances, and cars—and are crucial for automated manufacturing systems.
Why Choose Us
As an original manufacturer with over 13 years of experience, we specialize in designing and manufacturing passive RFID (NFC, HF, and UHF) tags for applications in inventory, laundry, access control, identification, and industrial automation management.
We are a pioneering leader in RFID technology and smart product solutions. For nearly 20 years, we have been at the forefront of custom RFID and NFC technology, offering innovative solutions in every imaginable form. Our expertise lies in developing and producing RFID/NFC products that are tailored to meet your specific requirements.
As the world’s leading RFID supplier, our factory is passionate about RFID technology. We deliver a wide range of products, including NFC tags, NFC cards, RFID/NFC labels, RFID inlays, various apparel tags, laundry tags, and RFID devices, to clients around the globe. Our RFID products are widely used in marketing campaigns, healthcare monitoring, workforce management, stock control, access control, apparel systems, laundry systems, inventory systems, IoT systems, and security applications.
Our Benefits
We provide products with competitive pricing and reliable quality, backed by an after-sales warranty. Whether you are a distributor, system integrator, or end-user, you will find the right RFID and related products here, ensuring that your company gains tangible benefits.
We have grown into a company with over 200 team members, including a production department, R&D center, sales department, technical support, and after-sales service. Understanding that time is of the essence, we can fulfill customized orders within just 5 days. Our dedicated team of over 100 factory staff ensures a stable supply and fast delivery for all our orders.
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