The credit management in Xoda's old plan builder (V0 Plans) work as follows:

1. The credit balance = this week's balance + remaining credits (unused credits accrued from previous weeks)
2. This week's balance is strictly for this week according to the plan. We do not support a member trying to access next week's credits while she or he is still in this week. Even if that member's debit has been processed, we still work by the concept of weeks based on plan start date. The credit calculation is not based on payment terms. If a member tries to access the next week's credits on the Sunday of the previous week, this will not work. If she waits a day then book on Monday, it will work for her.
3. Remaining credits: At end of each week, we have a weekly batch job that work out how many unused credits are left over from the current week's balance then add those unused credits to the remaining credits balance for the coming week.

Please note the credit management of our new plan builder (V1, a paid Xoda feature) allows a member to book into the future using the per term (for example per week credits).