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

# TransferInternalBalanceInput

> Input type for a transfer between user cash balance accounts.

**Input object**

Input type for a transfer between user cash balance accounts.

## Input fields

<ParamField body="idempotencyKey" type="UUID!" required>
  A unique client generated UUID to ensure a request is processed only once.
</ParamField>

<ParamField body="amount" type="Float!" required>
  The amount to transfer.
</ParamField>

<ParamField body="sourceUserCashBalanceId" type="UUID!" required>
  Unique identifier for the user's *source* cash balance.
</ParamField>

<ParamField body="destinationUserCashBalanceId" type="UUID!" required>
  Unique identifier for the user's *destination* cash balance.
</ParamField>

<ParamField body="memo" type="String">
  Memo for the transfer. Limited to 255 characters.
</ParamField>

<ParamField body="transactionCategory" type="String">
  Optional category name to attach to this transfer transaction.
</ParamField>

<ParamField body="attachmentId" type="String">
  ID of a previously uploaded attachment (PDF or PNG). Use the /api/v1/file-upload/transaction-memo-attachment endpoint to upload.
</ParamField>