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

# Identifiers

The Identifiers product returns the account number, routing number, and related identifiers for a customer's financial account. Use it to ensure that subsequent transactions (such as ACH transfers) end up in the right place.

<Note>
  **API Reference**

  * Search financial accounts: `GET /bank-linking/accounts`
  * Get a specific financial account: `GET /bank-linking/accounts/{accountId}`
</Note>

## Overview

Each checking or savings account is assigned a unique account number and routing number.

* **Account number** — Identifies your customer's unique bank account. Typically a 10–12 digit string that tells the bank which account to withdraw funds from or deposit funds in.
* **Routing number** — A nine-digit number that financial institutions use to identify other financial institutions. It indicates which bank holds your customer's financial account.

## Use cases

There are many use cases that require a customer's account and routing number, such as:

* Your app allows users to cash out a credit balance to a bank account.
* Your app allows users to pay you directly from their checking or savings account.
* Your app allows an end-to-end ACH transfer.

Account authentication lets you request a customer's account number and bank identification number (such as routing number, for US accounts) in a seamless and validated way without having to look up and type their account numbers.

<Note>
  Account authentication generally supports checking and savings accounts only.
</Note>

## Account authentication data

When calling the financial account endpoint, you can access the `accountNumber` and `routingNumber` for that account. See [Retrieving Connection Data](/docs/bank-linking/get-connection-data/retrieving-connection-data) for an example.

<Warning>
  **Tokenized Account and Routing Numbers**

  Service providers may provide "tokenized" account and routing numbers when working with institutions that support an OAuth flow. This may be due to the provider's or institution's policies. A tokenized account number is not the actual number but a representation of it. These tokenized numbers work identically to normal account numbers.

  The digits returned in the `mask` field continue to reflect the actual account number, not the tokenized account number. For this reason, when displaying account numbers in your UI, always use the `mask` rather than truncating the account number. If a user revokes permissions to your app, the tokenized numbers will continue to work for ACH deposits but not withdrawals.
</Warning>

## Sample response

```json theme={null}
{
    "id": "W9ja25UmrZF25xbG22wdd",
    "accountId": "W9kbkRme9VT2iz6qdsaww2",
    "customerId": "W9ja24edcTHBks8h2e2dww",
    "institutionId": "Ntj3AwgdridJc2rasdssdd",
    "institutionName": "Chase",
    "status": "ACTIVE",
    "type": "DEPOSITORY",
    "subtype": "CHECKING",
    "name": "Checking",
    "truncatedAccountNumber": "1234",
    "identifiers": {
        "ach": {
            "accountNumber": "00100000034561234",
            "routingNumber": "023000797"
        },
        "eft": null,
        "international": null,
        "bacs": null
    },
    "balances": {
        // data
    },
    "owners": [
        // data
    ],
    "serviceProviderDetails": [
        // data
    ]
}
```