To redeem a prepaid code, follow these steps:
1. Sign in to https://secure.backblaze.com/user_signin.htm with the registered Backblaze account email address and password.
2. Choose "Billing" from the navigation on the left hand side.
3. On the right of "Billing" use the "Buy" or "Change Payment Method" link.
4. On the pane that appears, choose "Prepaid Code" and enter the code into the field that appears.