Top-up

A top-up is the act of adding funds to a credit wallet once its balance runs low or hits zero — through a one-click payment link, an auto-charge the customer has explicitly opted into, or a manual payment initiated by the customer or their team.

It matters because the top-up moment is the single highest-leverage screen in a usage-based product: it happens exactly when a customer is about to be blocked from using the product they're paying for, which makes it either a moment of friction that costs a renewal, or — done well — a low-friction, almost invisible non-event.

In practice, a well-built top-up flow watches the wallet balance continuously and fires before the balance actually hits zero: a threshold alert with a one-click link gives the customer a fast path to add funds, an opted-in auto-charge removes the need for a click entirely, and a clear, non-punitive message explains what happens if neither fires in time.

The common pitfall is treating auto-charge as the default rather than an opt-in — silently charging a stored card without explicit prior consent erodes more trust than a momentary block ever does, even though the intent (avoiding disruption) is the right one. The charge itself has to be something the customer chose, not something that happens to them.