Labels & barcodes
How barcode and article reference allocation works
2 min readUpdated 8 January 2026PostVery product team
A duplicated article number is one of the few shipping mistakes that cannot be fixed after the parcel leaves. Allocation deserves the same care as handling money.
Reference series
A reference series is a block of numbers issued to your account for a particular service. Software should record the series range, the service it belongs to and how much of it has been consumed.
Four rules for safe allocation
- 1Allocate inside a transaction: a number is marked consumed in the same operation that attaches it to a shipment.
- 2Never reuse: a voided number is marked unusable, not returned to the pool.
- 3Reprints keep the original number and are logged as reprints.
- 4Every allocation records who did it and when, so a dispute can be traced.
Two operators, one series
The classic failure is two packers printing at the same time and receiving the same next number. Allocation must therefore be serialised at the database level, not calculated in the browser from a cached counter.
What a good allocation log shows
- Reference, shipment, order, operator and timestamp
- Status: allocated, printed, reprinted, voided
- Remaining capacity in the series, with a warning threshold
Demo references shown anywhere on this website are clearly marked sample values and are not live article numbers.