Open a subledger

What you will learn

✅ How to open a subledger (also called a subaccount)

You can open a subledger under any master account, such as a checking or savings account.

Subledgers also support a beneficiary profile for storing additional data such as the name and address associated with the subledger. Your Integration manager will assist you with any questions related to the data used to populate these fields, as they can vary by use case and program.

Once opened, the subledger is ready within a few seconds.

If you are new to subledgers we recommend you read the subledger documentation before starting this tutorial.

The tutorial assumes you have a knowledge of APIs and how they work. Refer to API basics for more details.

The tutorial uses these API endpoints:

API	Description
POST /core/v1/dda/subaccounts	Opens a subledger under a master account

Before you begin

Make sure you have:

API credentials

Master account number of the account under which you want to create the subledger

Title for the account

Registered for the following webhook event:

Webhook	Description
Core.SubAccount.Opened	Subledger (subaccount) was opened

Open a subledger

This tutorial shows you how to open a subledger for a master account. You will open an account for Jerry Penn, whose master account number is 2819503463.

To open a subledger

Call POST /core/v1/dda/subaccounts. For this call, the master account number and the title (name on the subledger) are required. Typically you use the partner name for the subledger title.

curl --location 'https://sandbox.crbcos.com/core/v1/dda/subaccounts' \
--header 'Idempotency-key: 3392de17-6e92-4999-b943-cad5f19b1629' \
--data '{
  "masterAccountNumber": "2819503463",
  "title": "Jerry Penn",
  "customerId": "53c34cf0-4cd2-4768-937b-b30000dffdca",
  "beneficiary": {
    "firstName": "Jerry" ,
    "lastName": "Penn",
    "streetAddress1": "12 Main St",
    "city": "New York",
    "state": "NY",
    "postalCode": "10001",
    "countryCode": "US"
  }
}
'

A successful API call returns a JSON response with the details of the new account.

{
    "accountNumber": "302022615264",
    "accountType": "Deposit",
    "status": "Active",
    "ledgerType": "Passthrough",
    "productType": "Checking",
    "title": "Jerry Penn",
    "currentBalance": 0,
    "availableBalance": 0,
    "holdAmount": 0,
    "transactionCount": 0,
    "creditLimit": 0,
    "currency": "usd",
    "openedAt": "2025-06-24T03:05:04.7952946-04:00",
    "masterAccountNumber": "2819503463",
    "customerId": "53c34cf0-4cd2-4768-937b-b30000dffdca",
    "beneficiary": {
        "firstName": "Jerry",
        "lastName": "Penn",
        "streetAddress1": "12 Main St",
        "city": "New York",
        "state": "NY",
        "postalCode": "10001",
        "countryCode": "US"
    },
    "partnerId": "cd9c12f4-7691-424a-b38b-af5b0134c611",
    "lastMaintenanceAt": "2025-06-24T03:05:04.7952946-04:00",
    "productId": "83bed086-8182-4151-a1e3-af5b01362783",
    "lastModifiedAt": "2025-06-24T03:05:04.8043224-04:00"
}

The accountNumber field provides the account number for the new subledger.

The Core.SubAccount.Opened webhook event fires when the account is open.

{
  "id": "7dffc503-e24b-4fdd-96c3-b2e20129aa6d",
  "eventName": "Core.SubAccount.Opened",
  "status": "Pending",
  "partnerId": "cd9c12f4-7691-424a-b38b-af5b0134c611",
  "createdAt": "2025-06-24T03:05:04.8043224-04:00",
  "resources": [
    "core/v1/dda/subaccounts/302022615264"
  ],
  "details": [
    {
      "subAccountNumber": "302022615264",
      "masterAccountNumber": "2819503463",
      "accountType": "Deposit",
      "status": "Active",
      "title": "Jerry Penn",
      "clientIdentifier": null
    }
  ]
}