To reach pages restricted to members, you must enter your certificate number and PIN. Certificate#: PIN: Remember these values? Note: Effective November 1, 2012 Logon using ZIP will no longer be available. To use your PIN, click here and follow the instructions to activate PIN.If you have created a security question you must use your PIN, not your zip code to logon. If you are having problems, go to the security information pages. If you are having trouble with the certificate number, "Clear Form" and try again. Hint, Leading Zeros should be included. A regular certificate number must be 7 characters. Please take a minute to read the USPS Website Privacy Policy. If you get stuck send us comments or Contact the USPS hotline at 1-888-FOR-USPS. Go directly to: the USPS Home Page