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

# How-to: Use Forwarding Service

> Use Forwarding Service when spending from a Unified Balance

You can use the
[Forwarding Service](https://developers.circle.com/cctp/concepts/forwarding-service)
when spending from a Unified Balance on the destination blockchain. When
enabled, it fetches the attestations from source blockchains and submits the
mint on the destination blockchain. You don't need to poll for attestations or
have access to a wallet on the destination.

## Prerequisites

Before you begin, ensure that you've:

* [Installed the App Kit SDK](/app-kit/tutorials/installation)
* [Configured an adapter](/app-kit/tutorials/adapter-setups)

These are required so any example below runs with a valid `kit` and `adapter`.

## Use with adapters on all blockchains

Set `useForwarder: true` when you have adapters on all source and destination
blockchains but want the Forwarding Service to submit the mint transaction on
the destination:

```typescript TypeScript theme={null}
const result = await kit.unifiedBalance.spend({
  amount: "1.00",
  from: {
    adapter,
    allocations: [{ amount: "1.00", chain: "Base_Sepolia" }],
  },
  to: {
    adapter,
    chain: "Arc_Testnet",
    useForwarder: true,
  },
  token: "USDC",
});
```

## Use without a destination adapter

When you don't have access to a wallet on the destination blockchain, such as
with server-side or custodial spend flows, omit the destination adapter and pass
`recipientAddress` with `useForwarder: true`:

```typescript TypeScript theme={null}
const result = await kit.unifiedBalance.spend({
  amount: "1.00",
  from: {
    adapter,
    allocations: [{ amount: "1.00", chain: "Base_Sepolia" }],
  },
  to: {
    chain: "Arc_Testnet",
    recipientAddress: "0xRecipientAddress",
    useForwarder: true,
  },
  token: "USDC",
});
```

In this mode, the Forwarding Service submits the mint transaction for you. Use
the spend result's `transferId`, `txHash`, or `explorerUrl` fields to track the
destination mint when they are returned.

## Forwarding fee

The Forwarding Service charges a
[fee](https://developers.circle.com/cctp/concepts/forwarding-service#fees-and-execution)
that is deducted from the amount minted on the destination chain. When you
[estimate spend fees](/app-kit/tutorials/unified-balance/estimate-spend-fees)
for a spend transaction, the result includes the forwarding fee. See
[How Unified Balance fees work](/app-kit/concepts/unified-balance-fees) for
details.