# Account Owner
source: https://developer.mastercard.com/open-finance-au/documentation/products/verification-account-owner/index.md

Tip: Accessing user data (account data, transactions, reports, etc.) requires user consent. For more about consent please check the [consent](https://developer.mastercard.com/open-finance-au/documentation/consent/index.md) page.

The [Get Account Owner](https://developer.mastercard.com/open-finance-au/documentation/api-reference/index.md#GetAccountOwner) endpoint retrieves account ownership details from a connected account at a financial institution.

Call the endpoint with a `customerId` and `accountId` to return the account ownership information.

API Reference: `GET /aggregation/v3/customers/{customerId}/accounts/{accountId}/owner`

Note: This endpoint only returns the details of the consenting individual or business. For example, if an account is a joint account and only one account owner has consented, the response does not include any details of the other account owner.

A successful response includes detailed information about the account owner including:

* Account holders
* Addresses
* Email addresses
* Phone numbers

<br />

The fields returned depend on whether the owner is an individual or a business (as indicated by the `type` field).
Note: A successful response will always include at least one `holder` containing `ownerName` and `lastName`.   

The remaining fields (such as `ownerAddress`, `email`, and `phone`) depend upon the financial institution providing the data and may not be available in some cases.

### Understanding Joint Accounts {#understanding-joint-accounts}

When working with accounts that may have multiple owners, you can use these fields returned by the Customer Account(s) endpoints (such as [Get Customer Account by ID](https://developer.mastercard.com/open-finance-au/documentation/api-reference/index.md#GetCustomerAccount)) to understand the ownership structure:

* **`isOwned`** - Indicates if the consenting customer is an owner of the account (`true` if they are an owner).
* **`accountOwnership`** - Indicates the number of account owners (`UNKNOWN`, `ONE_PARTY`, `TWO_PARTY`, `MANY_PARTY`).

### Recommendations {#recommendations}

When verifying ownership of a financial account, the following best practices are recommended:

* **Name** : Only `ownerName` and `lastName` are required for a successful account owner response and will be included by all data providers that support this product. The `firstName` field is not returned in some cases (for example, if the person only has one name).
* **Address** : While `ownerAddress` is provided by a majority of data providers, it is not required for a successful account owner response. Many providers also provide the address value broken down into individual fields; if you choose to create rules against optional address fields such as `line1`, `city` and `postalCode`, we recommend falling back to the `ownerAddress` value in the event other fields are unavailable.