Partition Value

What is the partition value?

The partition value is a 3-bit number (0–6) that appears in most EPC schemes right after the filter value. It solves a fundamental problem: GS1 company prefixes vary in length (6 to 12 digits), but binary fields must be fixed-width.

The partition value is a lookup key into a table that says: "the next N bits are the company prefix, and the M bits after that are the item reference." The total (N + M) is always fixed for a given scheme - the partition just moves the boundary.

Why it exists

A company with a short prefix (e.g. 6 digits) has more product numbers available but needs fewer bits to encode the prefix. A company with a long prefix (e.g. 12 digits) needs more bits for the prefix but has fewer product numbers. The partition allows both to fit into the same fixed-width binary field.

Without the partition, you cannot decode the EPC. You would not know where the company prefix ends and the item reference begins. This is why the partition is stored on the tag alongside the data.

Example: SGTIN-96 partition table

In SGTIN-96, the company prefix and item reference together occupy 44 bits. The partition value determines how those 44 bits are divided:

A company with a 7-digit prefix (e.g. 0614141) uses partition 5. The prefix takes 24 bits, leaving 20 bits (6 digits) for the item reference. Each scheme has its own partition table - see the individual scheme pages for the full tables.

Where it appears

The partition value is not visible in either URI form. It is a binary encoding detail needed only to decode the raw hex. Once decoded, the company prefix and reference are separate fields in both the Tag URI and Pure Identity URI.

In the binary layout, it typically occupies bits 11–13 (immediately after the 3-bit filter). Not all schemes have a partition field - GID-96 and ADI-var use different structures.

Source

GS1 EPC Tag Data Standard, Release 2.3, Section 14.6 (partition tables for each scheme).