> ## Documentation Index
> Fetch the complete documentation index at: https://docs.privy.io/llms.txt
> Use this file to discover all available pages before exploring further.

# Overview

> Understand how Privy meters usage and invoices metered charges

Privy supports two billing models for the costs an app incurs through wallet activity. Prepaid billing draws down a balance the app tops up in advance. Postpaid billing meters usage as it happens and invoices it at the end of the month.

## Setup

### Choosing your plan

| Model                 | How it works                                                                              | When usage is paid for              |
| --------------------- | ----------------------------------------------------------------------------------------- | ----------------------------------- |
| Prepaid (default)     | Sponsored gas draws down the app's [gas credits](https://dashboard.privy.io/gas-credits). | In advance, as a top-up             |
| Postpaid (Enterprise) | Privy meters each charge and adds it to a monthly invoice.                                | In arrears, at the end of the month |

<Note>
  Postpaid billing is available on the Enterprise plan. Contact
  [sales@privy.io](mailto:sales@privy.io) to enable it for an account.
</Note>

### Purchasing credits (prepaid)

An account on prepaid billing tops up its balance in the [gas credits dashboard](https://dashboard.privy.io/gas-credits). The balance must cover a sponsored transaction, and Privy rejects the request once it runs out.

<Info>
  To query prepaid gas credit consumption for a set of wallets, use the [gas spend
  endpoint](/wallets/gas-and-asset-management/gas/gas-spend).
</Info>

## Metering charges (postpaid)

Postpaid billing meters two kinds of usage independently. Each one becomes its own line item on the monthly invoice.

| Usage type      | What it covers                                                                                                                                                                                              |
| --------------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| Gas sponsorship | Network gas the app sponsored for a transaction, on apps that use [gas sponsorship](/wallets/gas-and-asset-management/gas/overview).                                                                        |
| Cross-chain     | Swap and slippage fees for executing a cross-chain [transfer](/wallets/actions/transfer/bridging) or [swap](/wallets/actions/swap/overview), on [fixed-rate routes](/wallets/actions/transfer/fixed-rates). |

A single wallet action can produce more than one charge. A sponsored cross-chain transfer meters both its gas and its routing cost.

## Consuming charge events

Privy publishes a webhook each time it records a charge, carrying the amount and the wallet action that incurred it.

<Card title="Usage webhooks" icon="webhook" href="/wallets/gas-and-asset-management/usage-billing/usage-webhooks" arrow>
  Receive an event each time Privy records a charge, and reconcile it against a wallet action.
</Card>