Please note that for Postal Codes the second character needs to be a 'number' not a 'letter', and in the second set of three characters, the 1st character is a 'number'. For example A3A 4G8, and the last character needs to be a number. (Lower case characters will be converted into upper case characters for you, and we correct the letter 'O' to a zero for you.) Otherwise, if you type the characters wrong you will likely be shown an error message.
If you get an error message, then likely you have entered a letter where a number needs to be, or a number where a letter should be. Just fix it and then click on 'search'.