All Things You Might Not Know About Gen 2 RFID Tag Memory Banks

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As we all know, RFID Tag Memory Banks is divided into read-only and read-write. The chip that can write data shows that it provides a storage area for users. Different chips have different storage area structure. This article mainly introduces GEN 2 RFID tag memory banks.

UHF Gen 2 RFID tags have four memory banks:

1.    EPC

2.    TID

3.    USER

4.    Reserved

EPC Memory:

The memory bank stores an EPC code or an electronic product code. It’s a minimum of 96 bits of writable memory. If most applications require only 96 bits of memory, EPC memory is typically used. Some tags have the power to allocate more bits from user memory to EPC memory. EPC memory is your first writable memory library.


  • The tag EPC number is stored in this area, where the 0th word is the PC value and the CRC16 of the tag EPC number. The first word is PC value; this value indicates the length of the EPC number of the tag, starting from the second word is the real EPC area card number of the tag (read and write) Note: The card number in the EPC area must be modified and read from the second word
  • EPC stands for “Electronic Product Code” not to be confused with UPC, and UPC stands for “Universal Product Code”
  • The length of the EPC number ranges from 96bit to 496bit. The most common EPC lengths are 96bit and 128 bit
  • Some chipset manufacturers make their EPC numbers unique, while others do not. Please be aware of this when purchasing RFID tags. If the tag you purchased does not have a unique EPC, it will look as if there is only one tag in the report’s read field when the tag is read. If the EPC of the tag is not unique, you can use an RFID printer (if it is an inlay or RFID tag) or encode the tags one at a time to encode them as unique values.
  • Unless the EPC storage area is locked, the EPC value can be read and rewritten as many times as necessary.
  • When placing RFID tags on items in certain applications (such as supply chain or retail), the EPC number will be encoded using an identification scheme. The EPC identification scheme was created by GS1 and explained how to encode the EPC number according to the project’s purpose. Set up an identification scheme to explain the bit allocation of the EPC number, and define the title, filter value, partition, company prefix, item reference, and digits in the serial number. These plans were created to standardize EPC allocations and are used in industries such as the Department of Defense and areas such as Global Trade (GTIN) and Global Returnable Assets (GRAI).

TID Memory

TID is the unique identification number of the chip. In general, this part of memory cannot be changed.


  • TID numbers are usually 32-80 bits long and contain the type and manufacturer of the chipset
  • Some tags have extended TID numbers, represented as XTID
  • Read-only
  • TID stands for “tag identifier” and should not be confused with the serial number or SGTIN (universal identification scheme)

User Memory:

The user area is used to expand more memory, and there is no standard for how many bits of memory can be written on each label when it comes to user memory. Typically, extended memory does not exceed 512 bits, but some high memory labels have up to 4K or 8K bytes of memory.


  • The user store provides a location for user-defined data
  • Not all chipsets contain user storage, but if the label has user storage, the manufacturer leaves it blank
  • User memory ranges from 32 bit to more than 64K bit

Reserved Memory:

The bank stores delete passwords and access passwords (each 32 bits).

The delete password permanently disables the label (rarely used), and the access password is set to lock and unlock the write function of the label.

This stick of memory is writable only if you want to specify a password.

Most users will not use this area of memory unless their application contains sensitive data.

Except for these two codes, it cannot store information.


  • Kill, and Access passwords are stored in a reserved storage area (00)
  • Both access and kill passwords are 32 bit long


If you have any questions about the second generation tag memory or anything related to RFID, please contact us

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