Changing your credit card information or method of payment
In most cases, all billing updates can be processed through the settings in your dashboard. If you need to change payment methods or require assistance, we would be happy to help here
From the Billing section of your Sucuri dashboard, https://login.sucuri.net/settings/billing/, click the link under your product:
From here on the right side you can click Edit above your current billing information.
You can modify your payment method and click Update Billing Information.