**Aurora operates on a prepaid payment model**, meaning that users must pay upfront for purchase of both **subscription plans and tokens**. Here’s how billing works in different scenarios:

Workspaces may experience fluctuations in the number of users throughout a subscription period. If additional users are added or removed in the middle of a billing cycle, the charges will be adjusted accordingly: - **New users added mid-cycle**: The workspace will be charged for the additional users starting from the next billing cycle, along with a prorated charge for the days they were active in the current cycle. - **Users removed mid-cycle**: If users are removed during a billing cycle, the workspace will not receive an immediate refund or adjustment. However, from the next billing cycle, the charges will reflect the updated number of users. > **Example**: If a workspace had **11 members in March** and **added 2 more users mid-month**, the April billing cycle will include charges for **13 users** plus an **adjusted charge for the days the 2 new users were active in March**.

Unlike a calendar-month-based system, Aurora follows a subscription anniversary billing model. This means that the billing cycle is determined by the exact date of the subscription purchase, not the beginning of the month. > **Example**: If you start a monthly subscription on **March 20th**, the next **auto-debit** will occur on **April 21st**. The renewal cycle will continue on this date every month thereafter.