Format and field rules
A postal box line normally uses PO BOX followed by its number, then the city, state, and ZIP Code.
A workflow that requires street delivery may explicitly reject PO Boxes. Explain the reason instead of silently converting a box into a street address.
Recommended test cases
Cover normal input, boundary input, and deliberately invalid input as separate cases.
- Accept common capitalization and spacing variants
- Validate the missing-box-number error
- Show a clear message when a shipping flow does not allow PO Boxes
Scope
This guide explains development-test formatting. It does not provide a delivery, identity, or payment verification result.
Authorship and review
- Written by
- Random Address Generator Editorial Team
- Reviewed by
- Data and Format Review Team
- Latest substantive update
- Reviewed the field rules, test examples, and scope for “US PO Box Address Format.”