All customers should be validated periodically to check for errors in their accounts. A good time to do this is just before each billing cycle. To do so:
1. Go to Utilities: Administration: Billing: Customers: Configure.
2. Click Validate all Customers.
3. A report will be generated showing any customer accounts that have errors (e.g., customer has no lists assigned; or no expiration date for credit card).
4. Click Editto change the customer information.