Each carrier has its own tracking format — UPS begins 1Z, USPS uses a twenty-digit number starting 94, Royal Mail ends with GB. A shipment tracking page that assumes one shape will fail on the rest.
What you can control
- Five carrier formats with their real prefixes and lengths.
- Status includes exceptions and label-created, the two states most tracking pages forget to design.
- Origin and destination are real city and region pairs, so a route map renders plausibly.
- Estimated delivery dates fall on both sides of today, which surfaces overdue-shipment logic.
What this is not
These match carrier formats but are not in any carrier's system. A tracking lookup will return no result — which is itself a case worth testing.
Questions
Will these numbers track anything?
No. They have the right shape and no corresponding shipment. Use them to test your form validation and your not-found state.
Why include exception statuses?
Because a delivery exception needs different treatment from in-transit, and a batch of happy-path shipments never reveals whether you built it.
Are the check digits valid?
No. Carriers use proprietary check-digit schemes that are not publicly specified. The formats are right; the checksums are not computed.