If the error involves values that the user can enter or modify (for example, text, settings, command-line parameters), then the error message should identify the offending value(s).
Not recommended
Funds can only be transferred to an account in the same country.
Recommended
You can only transfer funds to an account within the same country. Sender account’s country (UK) does not match the recipient account’s country (Canada).
Not recommended
Invalid postal code.
Recommended
The postal code for the US must consist of either five or nine digits. The specified postal code (4872953) contained seven digits.
If the invalid input is a very long value that spans many lines, consider doing one of the following:
- Disclose the bad input progressively; that is, provide one or more clickable ellipses to enable users to control how much additional error information they want to see.
- Truncate the bad input, keeping only its essential parts.
Multiple choice exercise
Which of the following error messages is best?
The specified bid is too low.
The specified bid is below the minimum bid ($8).
The specified bid (8).
The specified bid ($5) is too low.