Add funds and turn on auto top-up
Pay-as-you-go billing: add a card, load your balance, and set auto top-up so a call never dies mid-sentence.
ThunderPhone billing is pay-as-you-go: calls draw from your organization's balance at your agent's per-minute rate. No subscriptions, no seats. Everything on this page lives under Organization → Billing Settings.
1. Add a card
A card unlocks top-ups and phone numbers. It's only charged when you add funds — never automatically (unless you later opt into auto top-up).
2. Load your balance
Click one of the preset amounts ($25–$1000) or enter your own, then Add to balance — a confirmation dialog shows exactly what you're about to charge before you click Confirm and charge. Add at least $3.00 to start making real calls. Funds never expire.
3. Turn on auto top-up (optional, recommended)
If the balance hits zero mid-call, the call dies. Auto top-up prevents that:
- Enable the switch
Flip Enable auto top-up.
- Set the trigger and refill
Choose When balance falls below (the threshold) and Add amount (the refill). When the balance dips under the threshold, ThunderPhone charges your card for the refill amount.
- Optionally cap the month
Check Monthly spending limit to bound how much auto top-up can spend per calendar month.
- Save
Click Save changes.
Prompt-size surcharge
Per-minute call rates cover agent prompts up to 5,000 tokens. Larger prompts add a per-minute surcharge: each additional block of 10,000 tokens (or part of one) adds +1¢/min on Spark and +2¢/min on Bolt and Storm.
The surcharge is computed from the prompt actually used on each call.
That includes page context supplied by an embedded
web widget, which is capped at 12,000
characters (roughly 3,400 tokens of typical English text). The prompt
editor in the dashboard shows a live estimate while you edit, and each
call's billing-history entry breaks out widget-context tokens.
The complete pricing reference — base tiers, acknowledgements, extra intelligence, supervision, call metering, hold time, voicemail, simulations, and phone numbers — is at ThunderPhone pricing.
Watch the money
The Billing History tab lists every transaction — top-ups (manual and automatic), per-call usage, and monthly phone-number charges. The same data is available programmatically via the Billing API.