If you ever use passwords you know that you can only put in 3 a day, but you can get everything that you want using codes in one day. After you use all 3 passwords possible for one day, go to your Gyroid and save. Then choose Save & Quit, then when it reloads the title screen log back in on the account the stuffs in and go back to the passwords in Nook's store and you are able to put more in. This is helpful when using the 30,000 Bells code over and over to pay something off. Also, that way you can win even more points on the Happy Room Academy.