This address validation icon indicates that an address should be reviewed before shipping the order. It doesn't always mean that the address is invalid; the address could be valid but still should be reviewed, possibly edited and manually validated.
Why is the icon displayed?
1. Address is invalid (not deliverable). In this case, manually verifying the address will return invalid. This is usually due to if a customer has entered incorrect address.
2. Valid address with warning (some details aren't fully provided or entered in standardized format. E.g. excessive abbreviation or missing apartment number or missing apartment number prefix). In this case, manually validating the address will provide a valid address but it is uncertain exactly which door the package is to be delivered.
3. Address is valid but ambiguous because multiple addresses are found that share the same 5-digit ZIP. In this case, manually validating the address will provide a valid address, but it is uncertain to which address the package will be delivered.
What is the solution?
It is highly important that you ship a package to the correct destination. Therefore, the solution for bad or invalid address is to review and correct the address. Contact the customer if necessary, and always validate an address after correcting it.
Processing orders page provides you a warning when there are orders that need attention. Simply click the warning section to expand it and click on the See bad addresses link to view and correct addresses for multiple orders at once.