---
title: "Add Funds to Cards Sub-Wallet"
method: POST
path: "/sub-wallets/cards-settlement/transfers"
---

# Add Funds to Cards Sub-Wallet

`POST /sub-wallets/cards-settlement/transfers`

## Request

- Base URL: `https://api-sandbox.straitsx.com/v1`
- URL: `https://api-sandbox.straitsx.com/v1/sub-wallets/cards-settlement/transfers`
- Auth: API key in header `X-XFERS-APP-API-KEY`

[Available in Production/Sandbox environment] Transfer funds from the merchant's main wallet to their Cards sub-wallet. Supports same-currency transfers and fiat-to-stablecoin 1:1 conversions.

## Headers

- `X-XFERS-APP-API-KEY` string, required
- `X-PUBLIC-KEY-ID` string
- `X-TIMESTAMP` string
- `X-NONCE` string
- `X-SIGNATURE` string

## Request body

- object
  - `data` object
    - `attributes` object
      - `amount` string, required: Amount to transfer.
      - `currency` 'xsgd' | 'usdc' | 'xusd', required: Destination sub-wallet currency.
      - `walletSource` 'xsgd' | 'usdc' | 'xusd' | 'sgd' | 'usd': Source wallet currency. Use `sgd` or `usd` for fiat-to-stablecoin 1:1 conversion.<br><br><strong>Note:</strong> If omitted, defaults to the same value as `currency` (same-currency transfer).
      - `idempotencyId` string, required: Unique ID for deduplication.

## Response `201`

201

- object
  - `data` object
    - `id` string: Transaction reference ID.
    - `type` string: Resource type.
    - `attributes` object
      - `idempotencyId` string: The idempotency ID provided in the request.
      - `transactionType` string: Type of transaction.
      - `amount` string: Amount transferred.
      - `currency` string: Currency of the transfer.
      - `status` 'completed' | 'pending' | 'failed': Transaction status.
      - `createdAt` string: ISO 8601 timestamp of creation.
      - `updatedAt` string: ISO 8601 timestamp of last update.

## Changes

- **2026-11-03** `d17239d67150`: 1 info
  - endpoint added

[Operation history](https://skmtc.dev/straitsx/apis/straitsx-sandbox-base-url/changes/sub-wallets/cards-settlement/transfers/post.md)

---

[API](https://skmtc.dev/straitsx/apis/straitsx-sandbox-base-url.md) - [All operations](https://skmtc.dev/straitsx/apis/straitsx-sandbox-base-url/llms.txt) - [OpenAPI document](https://skmtc.dev/straitsx/apis/straitsx-sandbox-base-url/revisions/d17239d67150?raw)