#tracking-numbers
2 posts
UPU S10 Tracking Number Format Explained: 2 Letters + 9 Digits + 2 Letters Country Code
The international S10 postal tracking format decoded — 2-letter service indicator, 9-digit serial with check digit, 2-letter ISO country code. Examples, validation, and the check-digit formula.
Understanding Tracking Number Formats by Carrier
A comprehensive guide to tracking number formats from major carriers worldwide. Learn how to identify carriers from tracking numbers automatically.