# ABU Pull Inquiry Model
source: https://developer.mastercard.com/automatic-billing-updater/documentation/usecases/pull-inquiry-model/index.md

## How It Works {#how-it-works}

You may make an on-demand inquiry to ABU to check for the latest account credentials for your customer's payment account stored in your system.

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For optimal chances of a successful payment transaction, we recommend checking for account updates before you make the transaction if you are not already subscribed to receive automatic updates. Alternatively, you may also check for account updates if your card-not-present transaction was declined due to outdated payment account credentials.

![abu-pull-how-it-works](https://static.developer.mastercard.com/content/automatic-billing-updater/documentation/images/abu-pull-how-it-works.png)

1. Send an account inquiry request to ABU with the payment account information (account number and expiry date).
2. The account number (PAN) is queried against the ABU database to identify if there are updates immediately available (for example: account number change, expiry date change, or account closure). The API response back to you will contain the updated account credentials, if any.

ABU will respond with one of the following possible response types:

|             Account Inquiry Response Type              |        ResponseIndicator         |                                                                                               Description                                                                                                |
|--------------------------------------------------------|----------------------------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| Account is up-to-date                                  | `VALID`                          | No updates available. Submitted account number \& expiration date matches information in ABU database                                                                                                    |
| Update available (information provided is not current) | `EXPIRY` or `ACCOUNT_UPDATE`     | `EXPIRY` indicates a more current expiry date is available for the PAN. `ACCOUNT_UPDATE` means the PAN and expiry date have changed. Updated account number and expiry date are provided in the response |
| Account closed                                         | `CONTACT`                        | Account has been closed and should not be used for future payment transactions                                                                                                                           |
| Account not found                                      | `UNKNOWN` or `NON_PARTICIPATING` | Account is not available in ABU                                                                                                                                                                          |

Tip: Integrate with the [ABU Push subscription model](https://developer.mastercard.com/automatic-billing-updater/documentation/usecases/push-subscription-model/index.md) if you are interested to receive account updates from ABU automatically.

### Experience design guide {#experience-design-guide}

This flow diagram illustrates a checkout experience at a merchant's website for a returning customer. When a customer checks out with a saved payment method, the merchant can make an account inquiry to check for any updates to the saved account credentials.

Depending on merchant preference, this account inquiry may happen either before the payment transaction happens, in which the merchant proactively updates the account credentials prior to making the payment transaction, or upon a transaction decline as part of their retry strategy.

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### Example sequence {#example-sequence}

The following example sequence shows how you might use the account inquiry API. The expiry lifecycle event is shown in this example, but the flow is the same for any other lifecycle event.
Diagram pullrequest

More details on the technical API specifications can be found in [API Reference](https://developer.mastercard.com/automatic-billing-updater/documentation/api-reference/index.md).
Note: Pull inquiry model supports both API and bulk file integration options. You must also integrate with the bulk file for batch inquiries in addition to using the API for ad-hoc queries.

Details about integrating with ABU via bulk files are available in the [ABU Reference Guide](https://techdocs.mastercard.com/bundle/m_MAB) on Mastercard Connect.