SpamZilla credits are provided with the monthly subscription or when you purchase a Credits Pack.
Credits included with your monthly subscription are renewed each month, they do not roll over.
Credits you purchase with a Credits Pack will never expire until you use them.
1 domain = 1 credit
If the response from SpamZilla is an 'Error' you will not be charged a credit for that domain.
SpamZilla stores the domains you've previously processed, you will not be charged extra when processing the same domains multiple times.
Select the credits option in the profile menu on the upper right hand side of the screen.
From the below page, select one of the three credit packages to purchase.