In anticipation of monthly service renewals (for phone numbers (DIDs), E911, and associated Taxes, Surcharges, and Fees), we execute a payment 5 days prior to month-end to fund the monthly services renewal charges on the first day of the next month. We process this payment, which will differ in an amount from your auto-replenishment amount, to avoid service interruptions resulting from errors processing these payments. The amount we charge is based on your anticipated monthly renewal amount and the balance trigger you have set. If we determine that your upcoming monthly charges will put your balance below the trigger, then we charge the difference.
In the event of unexpected increase in usage on the account, we may charge a "Supplemental anticipatory auto-replenishment deposit for upcoming renewals". This feature is meant to keep the account at a healthy balance so it can absorb the renewal charges in between the initial anticipatory replenishment and the 1st of the month. The anticipatory charge is ran days ahead of time in case there are issues with the credit card, leaving you, a Flowroute customer, time to fix the problem. This creates days where the you could have usage which draws the balance below the point it could absorb the monthly charges. This supplemental charge will make credit card charges equal to the replenishment amount you have preset.
You can review this feature and check the amount under Preferences → Balance Management in the Manage Portal.