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

# 400 - Unsupported Address

An Unsupported Address error is returned when a request specifies a destination address that can never receive a transfer, regardless of amount or asset.

Endpoints that can return this error: [Create Crypto Withdrawal](/api-reference/endpoints/crypto-withdrawals/create-crypto-withdrawal), [Put Crypto Destination Address](/api-reference/endpoints/crypto-destination-addresses/put-crypto-destination-address).

An Unsupported Address error has the following `meta` fields:

* `address`: The destination address that is not supported.
* `reason`: A machine-readable code describing why the address is unsupported:
  * `INTERNAL_WITHDRAWAL_WALLET`: The address belongs to an internal Paxos withdrawal wallet. Paxos withdrawal wallets cannot be used as customer destinations.
  * `RESERVED_ADDRESS`: The address is a reserved network address — for example a native Solana program such as the System Program (`11111111111111111111111111111111`). Transfers to these addresses are rejected by the network itself and can never succeed.

The rejection is permanent for the given address — do not retry with the same address. To resolve this error, retry the request with a different, supported destination address.

<CodeGroup>
  ```json Example theme={null}
  {
    "detail": "unsupported address 11111111111111111111111111111111: RESERVED_ADDRESS",
    "meta": {
      "address": "11111111111111111111111111111111",
      "reason": "RESERVED_ADDRESS"
    },
    "status": 400,
    "title": "Unsupported Address",
    "type": "https://developer.paxos.com/docs/v2/problems/unsupported-address"
  }
  ```
</CodeGroup>