The whole organisation shares a single credit balance, shown at the top of Billing. Every call draws it down; every top-up and plan credit builds it back up. There are no usage invoices and no surprise bills — if the money isn't in the balance, the call doesn't happen.
One balance, plan rates
Calling is priced per minute by the plan. On the realtime models the Builder defaults to, that one rate covers the AI model, the voice and the telephony; pipeline models meter those parts separately, and the full rate card is in the dashboard. The same pricing applies whether the minutes come from included credit or a top-up, billed in 6-second increments — a 30-second call costs half a minute's rate.
Every movement — usage, top-ups, plan credits, refunds — appears in the Ledger tab on Billing, with a running balance after each entry. That is where the real money lives; the Usage page shows volumes, not charges.
Topping up
The button is on the page header and on the Credit balance card.
Preset amounts run £25 to £250. The modal shows the credit, the VAT and the total before payment — the balance is credited the amount picked, the payment method is charged that plus the VAT, and the Ledger records both.
Payment is a Stripe-secured form accepting cards, Apple Pay and Google Pay. The balance updates as soon as Stripe confirms — usually within a few seconds.
Saved payment methods live under Payment methods on the same page, where a card can be added, removed, or marked as the default.
Auto top-up
The Auto top-up card on Billing has a toggle and two amounts: When balance below and Top up by. When enabled and the balance dips under the threshold, the default payment method is charged automatically for the top-up amount.
Auto top-up isn't instant, so the threshold deserves a little headroom above zero where call volume is bursty. Pay-as-you-go accounts get it pre-configured at signup — see Choosing how you pay.
The hard stop at zero
At zero, calls stop — agents stop answering new calls until credit arrives, whether from a top-up or a plan renewal. That is the whole model: prepaid with a hard stop. The balance can never go negative.
Nothing else is touched when credit runs out. Agents, numbers, knowledge, call history and settings stay exactly as they were, the dashboard remains fully usable, and a top-up or plan change can happen at any point.
Credit that rolls over
Unused credit rolls over into the next month, capped at one month's credit — a quiet month isn't wasted, but credit can't pile up indefinitely.