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.
You can review this feature and check the amount under Preferences → Balance Management in the Manage Portal.