# Use Cases
source: https://developer.mastercard.com/automatic-billing-updater/documentation/usecases/index.md

Automatic Billing Updater (ABU) receives account lifecycle events from issuers and shares these events with you so that you can keep stored credential-on-file accounts updated. A lifecycle event happens when a new account relationship has been established between a cardholder and their issuer, or when an account's credentials have changed due to an expiry date change, closure, replacement, brand flip (for example from a non-Mastercard branded account to a Mastercard-branded account), or portfolio upgrade (such as when an account is upgraded from a Mastercard World tier to a World Elite tier).

ABU supports two types of integration models for you to obtain account updates:

1. Push subscription model
2. Pull inquiry model

You have the flexibility to choose which accounts you want to automatically receive update notifications for, and which accounts you want to inquire ABU on an on-demand basis to obtain updates for.

##### Push subscription model {#push-subscription-model}

You may choose to automatically receive account update notifications for payment credentials stored in your systems. To do this, you must subscribe to 'watch' an account. Notifications for all your subscribed accounts will then be sent via API to a designated endpoint whenever account updates are received from issuers.

To integrate with the Push subscription model, you need to implement a set of API endpoints that support subscription management. You also need to be ready to receive account notifications at the designated API endpoint set up during your onboarding process.

| Managing Your Subscriptions |                                                                                                                    Description                                                                                                                    |
|-----------------------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| Account Subscriptions API   | Subscribe to an account to automatically receive future updates [Learn more](https://developer.mastercard.com/automatic-billing-updater/documentation/usecases/push-subscription-model/index.md#subscribe-for-account-updates)                    |
| Subscription Deletions API  | Delete a subscription to an account to stop getting automatic future account notifications [Learn more](https://developer.mastercard.com/automatic-billing-updater/documentation/usecases/push-subscription-model/index.md#delete-a-subscription) |
| Subscription Inquiries API  | Check if you are subscribed to receive notifications for a given account or not [Learn more](https://developer.mastercard.com/automatic-billing-updater/documentation/usecases/push-subscription-model/index.md#check-subscription-status)        |

| Receiving Account Updates |                                                                                                                    Description                                                                                                                     |
|---------------------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| Notifications API         | Receive a push notification from ABU about updates on a given account that you are watching [Learn more](https://developer.mastercard.com/automatic-billing-updater/documentation/usecases/push-subscription-model/index.md#receive-notifications) |

Refer to [ABU Push subscription model](https://developer.mastercard.com/automatic-billing-updater/documentation/usecases/push-subscription-model/index.md) for more details on how this model works.
Note:   

* **Push subscription model is only offered through APIs.** Bulk file support is not available for subscribing and receiving push notifications. If you wish to obtain account updates through bulk files, you must integrate with the [Pull inquiry model](https://developer.mastercard.com/automatic-billing-updater/documentation/usecases/pull-inquiry-model/index.md).
* ABU does not support account subscriptions for Mastercard network tokens.

##### Pull inquiry model {#pull-inquiry-model}

To check for updated information for a given account, send an account inquiry request to ABU. ABU will respond with the most up-to-date information for the accounts that you have inquired upon.

ABU supports the pull inquiry model through two methods:

* **Batch** : the recommended approach for large volumes of account inquiries is to send ABU a bulk file request through your Mastercard Global File Transfer (GFT) endpoint. ABU processes bulk file requests once daily.  
* **API**: for urgent inquiries that demand an immediate response, use the Account Inquiries API to inquire on a single account number.

| Checking for Account Updates |                                                                                     Description                                                                                     |
|------------------------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| Account Inquiries API        | Check if there are available account credential updates [Learn more](https://developer.mastercard.com/automatic-billing-updater/documentation/usecases/pull-inquiry-model/index.md) |

Refer to [ABU Pull inquiry model](https://developer.mastercard.com/automatic-billing-updater/documentation/usecases/pull-inquiry-model/index.md) for more details on how this model works.
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.