Serial Numbering Systems

What a Numbering System Does

A serial numbering system assigns a unique number to each unit as it passes through production, prints it on the label or packaging, and records the assignment. The point is not generating numbers — that part is trivial — but guaranteeing that no number is ever issued twice.

Numbering Logic

Incrementing, date-based, prefixed by line or product group, or distributed and unpredictable where security matters. The logic is fixed once and preserved across all subsequent runs; changing it breaks matching against historical records.

Multi-line Synchronisation

When several lines run simultaneously they must not issue the same number. Two approaches work: a central counter that all lines request from, or reserved ranges allocated per line. The first is simpler to audit; the second keeps running if the network drops.

Power Failure

The most important resilience question. The last issued number is stored persistently, so when the system restarts it continues from there rather than restarting the sequence. Systems without this behaviour produce duplicate numbers after every outage.

Waste and Cancellation

Numbers on misprinted or rejected units go to a cancellation list and are never reissued. Reusing them would put two identical numbers into the field.

ERP Connection

Where numbers are generated must be decided once: either the ERP issues them and the print system only prints, or the print system issues and reports back. Both generating simultaneously guarantees collisions. See variable data solutions.