We check for the utilization of your paid resources every 24 hours. Depending on your utilization, the money due will be charged against the Credits available on your account. If you can predict your utilization, you can purchase enough credits in advance. If the bill calculated based on your utilization in the past 24 hours exceeds the amount of credits available on your account, the account will be considered delinquent and is immediately due for payment. We will process the difference to make your account current and send you a notification. You can now add more credits to your account. If credits are not added, and your billable resources continue to run, the next 24 hour check will again show your account as delinquent. This time we will process the difference again and pause your billable resources to ensure that the bill does not come to you as a surprise. You can then simply add more credits and resume your resources. You can also avoid this by enabling Auto Replenish from the Credits Page.