After you exhaust the quota of your resource plan, you are still charged for the billing item that corresponds to the resource plan.

For example, if you purchase a Standard locally redundant storage (LRS) plan of 40 GB and the storage usage of the Standard LRS objects in a bucket is less than or equal to 40 GB, you can use the storage plan to offset the generated fees. If the storage usage of the Standard LRS objects in a bucket is greater than 40 GB, you cannot use the storage plan to offset all generated fees. You are charged for the excess resource usage based on the pay-as-you-go billing method.