The most obvious answer is that your are entering the incorrect PIN. However, it may also be because you have set a password against your account. If this is the case you will be unable to login using the PIN (these can now only be used if parking using our mobile apps) and will return an error message stating "Login details are incorrect. If your account has a password set, please use that instead of your PIN."
This means that you are only able to access your online account by using your password. Adding a password gives customers additional security, although it is by no means compulsory.
If you do not know your password you will need to reset it using our online password recovery tool by entering the email address that is stored on the account. Should you have since changed email address or no longer have access to the stored email address, you should contact our Customer Care Team for assistance in resetting or removing the password.