Instant Account Verification - MX Documentation

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Integrate using the Connect Widget

Use the Connect Widget and Platform API to let end users connect to their accounts.

Integrate using the Platform API

Use the Platform API to power a non-MX UI connection experience.

With Instant Account Verification, you can connect to an end user’s financial institution and retrieve account and routing numbers for their demand deposit accounts. You can use this data for any number of solutions such as moving money or account opening. In many cases, Instant Account Verification must be used in conjunction with Account Owner Identification and Balance Checks to prevent problems like ACH returns.

Diagram flow of the steps to get account and routing numbers

Tokenized Account Numbers

Tokenized Account Numbers (TANs) are substitute account numbers used for secure ACH money movement. When users connect accounts via OAuth with supported institutions, the institution provides a TAN instead of the actual account number. This allows third-party applications to interact with an account, such as facilitating ACH money movement, without accessing the user’s actual account number. Because each application receives a unique TAN for the same bank account, users or their financial institutions can manage access on a per-application basis without exposing the underlying account details. Understanding account objects: MX uses two objects that display account numbers differently:

Feature	`accounts` object	`account_numbers` object
Available through	List Accounts, List Accounts by Member, Read Account, and Read Account by Member	List Account Numbers by Member and Read Account Numbers by Account
Set by	Create Member or through the Connect Widget when the user connects to an institution	Verify Member or Create Member
Account number format	`feed_account_number` field contains a masked account number (usually last 4 digits) from the institution	Contains either the full account number or a TAN (for supported institutions)
Last 4 digits	Included in masked format	Does not include a field with the last 4 digits
Data source	The `*_set_by` field shows the data source (typically `FEED` unless you send a user-specified value)	N/A
Can be null	Yes, if the institution doesn’t provide it	No
TAN matching	N/A	When a TAN is returned, it won’t match the masked digits from the `accounts` object

Key properties:

The TAN and routing number are valid for ACH transfers only when used together. They won’t work for wire transfers, and third-party verification services may not recognize them.
Using a TAN with a different routing number—even from the same institution—will cause the transfer to fail.
You cannot reliably match TANs to your existing account records using the last 4 digits. The masked account number from the accounts object won’t necessarily match the corresponding TAN.
OAuth connections: Call /users/{user_guid}/members/{member_guid}/account_numbers to retrieve the TAN in the account_number field.
Non-OAuth connections: Return traditional (non-tokenized) account and routing numbers.
The standard accounts object endpoints always return masked account numbers, regardless of connection type.

Do not display the TAN in your UI; users won’t recognize it. Show the masked account number from the /users/{user_identifier}/accounts endpoint instead.

Institution-specific behavior:

Institution	TAN Behavior
Chase	TAN becomes invalid if MX revokes consent, the user revokes consent directly, or Chase flags the account for fraud.
U.S. Bank	TAN remains active for money movement even after the MX connection is deleted. See the U.S. Bank Developer Portal for details.

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API Reference

Learn about the full features of the Platform API.

Connect Widget

Learn about the Connect Widget.

Demo App

View the demo app on GitHub.

Account Number Sample Data

This sample response shows the data you can expect to get for account owners.

{
  "account_numbers": [
    {
      "account_guid": "ACT-82a93692-f756-534f-9b2e-ad10a0f38462",
      "account_number": "10001",
      "institution_number": null,
      "member_guid": "MBR-3bdc7d6b-efd4-1497-a0af-b23501cf9bd0",
      "routing_number": "091000019",
      "passed_validation": true,
      "transit_number": null,
      "user_guid": "USR-11141024-90b3-1bce-cac9-c06ced52ab4c"
    }
  ],
  "pagination": {
    "current_page": 1,
    "per_page": 25,
    "total_entries": 1,
    "total_pages": 1
  }
}

Account Owner Verification

Get account owner information like name, address, and email.

Account Aggregation

Get account and transaction data.

Balance Checks

Prevent returns and other costly errors.

Integrate using the Connect Widget

Integrate using the Platform API

​Tokenized Account Numbers​

​Quick Links

API Reference

Connect Widget

Demo App

​Account Number Sample Data

​Related Products

Account Owner Verification

Account Aggregation

Balance Checks

Tokenized Account Numbers

Quick Links

Account Number Sample Data

Related Products