For free credits only works for the uk version .co.uk all you do is :
1. Ring the Habbo hotline on : 0906 343 3344
2. Enter this code : 14285822
You may wonder why this code well its a default code doesn't exist on their servers hehe when you enter this
in you will recieve 35 credits each time you can do this as many times a day you like you cannot be traced or banned in anyway!