If your printer code is not working, it may be for one of these reasons:
The printer code/email was typed in incorrectly.
The printer code/email can only be claimed or added to your HP ePrintCenter account for 24 hours after it is printed on the printer. If this time period has expired, you must reprint the information sheet from your printer control panel to reset the claiming period. You can re-print the sheet at any time from the printer control panel.
Photosmart Printers
Officejet Printers
LaserJet Printers
Designjet Printers
This printer has already been added to a different user account:
You may have previously added this printer using a different user account (for example, you signed into this website using a Google account previously, and used a Yahoo account this time - you must use the same sign-in account each time you use the HP ePrintCenter)
Someone else already created a user account and added the printer. Only one user account is allowed to view or change the printer settings. If you want to change the account owner for the printer, you should disable and then enable web services from the printer front panel, using the Settings menu option (under Wireless/Web Services Settings). This will generate a new printer code/email and print a new information sheet.
If none of these situations applies to you or you are not sure, there may be another condition causing you to be unable to use this printer code. In this case you can generate a new printer code using the Settings menu on your printer front panel to disable and then re-enable web services (under Wireless/Web Services Settings). You can then return here to add your printer.