Not every surprise is great!
In order to prevent bill shock and to manage credit, if your usage of services that are not included in your plan (such as pay-as-you-go charges, roaming, boosts - service availability depending on the monthly plan you are on) reaches the set credit cap in any month, you must make the relevant credit cap payment by using the Pay Now functionality in order to be able to continue to use non-included services.
Your Circles.Life Plan has a credit cap of $200.
If you do not make the relevant credit cap payment, you will still be able to make standard calls, SMS and data that are included in your plan, but you will not be able to use pay-as-you-go services that are not included in your plan until the credit cap payment is made.