---
title: Fund a sandbox account
slug: tutorials/fund-a-sandbox-account
docTags: 
createdAt: 2026-08-09T11:45:58.610Z
---

## What you will learn

✅ Different methods for depositing funds into a sandbox Cross River (COS) account

:::hint{type="info"}
The tutorial assumes you have a knowledge of APIs and how they work. For more information on sending API calls, see [API Basics](docId\:zg9CjGPbh9nMHCoit5W3a).
:::

## Before you begin

Make sure you have:

- [API credentials](docId\:wmg-1Fqwq3bj-D3c3HFfs)
- The account number of the sandbox [bank account](docId\:ZtQ-EXuMODfi9pu3z10FW) to be funded

## Fund a sandbox account

Depending on the payment rails your sandbox account is configured for, choose the payment method to put funds into that account.

Each of the endpoints listed below simulates funds coming into your sandbox Cross River bank account.

| Endpoint                                              | Description                                                                                                                                                               | Tutorial or API reference page                                                   |
| ----------------------------------------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | -------------------------------------------------------------------------------- |
| `POST ACH/v1/payments/simulated-inbound-originations` | Simulate an inbound ACH payment.<br />ACH payments in sandbox take several minutes to post.                                                                               | Tutorial: [Simulate inbound ACH](docId\:XiG1oe0IP7L9Q-Ii3U-Mk)                   |
| `POST /Wires/v1/payments/simulations`                 | Simulate an inbound wire transfer.<br />Wire payments in sandbox post almost immediately.                                                                                 | Tutorial: [Simulate an inbound wire](docId:22hF8HedChZVKiHnSFrYC)                |
| `POST /rtp/payments/simulated-inbound-origination`    | Simulate an inbound Instant Payment.<br />This endpoint can simulate any type of Instant Payment: RTP, FedNow, CRNow.<br />In sandbox, Instant Payments post immediately. | API reference page: [Simulate inbound origination](docId\:KBi-d7ioMPFVHQ3QlyC_h) |
| `POST /checks/v1/payments/simulated-inbound-payments` | Simulate depositing a check (outbound forward payment.<br />Check payments in sandbox take several minutes to post.                                                       | API reference page:[Simulate inbound payment](docId\:RI6dUmr8d8aQ-mle7tdzy)      |