# Subscription lists Create audience lists for specific topics. > **Important:** Please consult your legal counsel before implementing a particular subscription list approach or to help define the subscription purpose in order to address your specific use case or regulatory requirements in your jurisdiction. Audience Lists are messaging recipient groups based on either your own data or automatically-generated app user lifecycle information. You can use audience lists to target specific users. ## About subscription lists A *Subscription list* is an audience list of users who are opted in to messaging about a specific topic. Users can manage their opt-in status per list using a Preference Center. Subscription lists can help with retaining customers, since recipients can opt in and out of content per list rather than opting out of all messaging. After you create a subscription list, you can: * Select the list when defining your audience for a message * Opt a user in to or out of a subscription when the user taps a button in a push notification, in-app message, or web push notification * Trigger an [Automation](https://www.airship.com/docs/reference/glossary/#automation) or [Sequence](https://www.airship.com/docs/reference/glossary/#sequence) when a user opts in to or out of a subscription, or use their opt-in status as a [Condition](https://www.airship.com/docs/reference/glossary/#conditions_event_option) * Include the list in a [Segment](https://www.airship.com/docs/reference/glossary/#segment) * Include the list in a [Preference Center](https://www.airship.com/docs/reference/glossary/#preference_center) * Opt users in to or out of a subscription list when they respond with an [SMS Keyword](https://www.airship.com/docs/reference/glossary/#sms_keyword) --- A subscription list is for either commercial or transactional purposes, which you specify when creating the list and can edit at any time. * **Commercial** — Advertises or promotes a commercial product or service, including content on a website operated for a commercial purpose. * **Transactional** — Facilitates an already agreed-upon transaction, or updates a customer about an ongoing transaction. Verify with your legal team to comply with regulations. When you send to the list, you should only include content related to its purpose. When sending an **email** to a subscription list, you must include an unsubscribe link for opting out of all email messaging, and you can also include an unsubscribe link for that list only. See: [Email unsubscribe links](https://www.airship.com/docs/guides/messaging/messages/content/email/email-unsubscribe-links/). --- You create subscription lists in the dashboard, and you can add users using these methods: * **Automatically** — Enable [Auto opt-in](#auto-opt-in). * **Manually** — [Use the API to add or remove users](#populating-a-list-using-the-api). * **User choice** — Include the list in a [Preference Center](https://www.airship.com/docs/reference/glossary/#preference_center). > **Note:** Airship does not preserve the opt-in/out dates or the source of when or where a user opts into or out of a subscription. Airship does not have access to dates for opt-in/out events unless [Real-Time Data Streaming (RTDS)](https://www.airship.com/docs/reference/glossary/#rtds) is set up. See: [RTDS API: Subscription List Event](https://www.airship.com/docs/developer/rest-api/connect/schemas/events/#subscription-list). ### Auto opt-in [AXP](https://www.airship.com/docs/reference/feature-packages/) When creating a subscription list, you can automatically opt in users to that list by enabling *Auto opt-in*. Both existing and new audience members will be opted in to the list. Auto opt-in cannot be disabled after saving your list. Lists enabled for auto opt-in are not available for use with the *Subscription* trigger for Sequences and Automation. Changing the list type between commercial and transactional does not change the auto opt-in setting. ### Reporting In [Performance Analytics](https://www.airship.com/docs/reference/glossary/#pa), you can view a list's eligible subscriber count over time. This count is of unique users subscribed to the list and opted in to notifications at any time during the time frame defined for the report. Go to *Audience » Lists » Subscription* and click for a list. The default view is the last 30 days of data. Use the date filter to select a new time frame. Reporting is not available for lists enabled for [Auto opt-in](#auto-opt-in). ## Creating a list You can create up to 20 subscription lists per project. 1. Go to *Audience » Lists » Subscription* and click **Create subscription list**. 1. Enter a name and description for the list. Both appear in your project's [Preference Centers](https://www.airship.com/docs/reference/glossary/#preference_center). Description is optional. * The list ID is automatically generated based on the name and is truncated at 32 characters. * A list ID will not generate for a list name that contains only numbers and/or special characters. * If the name starts with a number and/or special characters, the generated ID omits the leading numbers and/or special characters. * Uppercase letters in the name are converted to lowercase in the ID. * Special characters in the name are converted to underscores in the ID and only appear if followed by numbers or letters. 1. (Optional) Edit the list ID. Letters, numbers, and underscores only, and must start with a letter and end with a letter or number. 32 characters maximum. **You cannot change the list ID later.** 1. Click **Next**. 1. Enable the channels you want to include in the list. 1. Select a subscription type: Commercial or Transactional. Commercial is selected by default. 1. (Optional) Check the *Auto opt-in* checkbox to enable [auto opt-in](#auto-opt-in). **You cannot change this setting after you save the list.** 1. Click **Save**. ## Populating a list using the API Subscription lists are set at the user level to support multi-channel preferences. Use the [Named User Scoped Batch Operations endpoint](https://www.airship.com/docs/developer/rest-api/ua/operations/named-users/#performnameduserscopedbatchoperations) to add or remove users to/from your subscription list. > **Note:** If you are using a single-channel [Preference Center](https://www.airship.com/docs/reference/glossary/#preference_center) created before October 10, 2022, that has not been [migrated to user-level](https://www.airship.com/docs/guides/messaging/features/preference-centers/#migrating-to-a-user-level-preference-center), use the [`/api/channels/subscription_lists` endpoint](https://www.airship.com/docs/developer/rest-api/ua/operations/channels/#modifychannelsubscriptions) to add or remove individual channels to/from your subscription list. ## Using subscription lists * **Message and experiment audiences** — Include a subscription list when using the **Target by conditions** or **Target Specific Users** option in a message, Feature Flag Configuration, or A/B test audience. To send to a subscription list using the API, use the [`subscription_list` atomic selector](https://www.airship.com/docs/developer/rest-api/ua/schemas/audience-selection/). * **Buttons** [AXP](https://www.airship.com/docs/reference/feature-packages/) — Opt a user in to or out of a subscription list when the user taps a button in your message. See [Add buttons to message content](https://www.airship.com/docs/guides/messaging/messages/buttons/#add-buttons-to-message-content) in *Buttons*. * **Automation and sequence trigger and condition** — Trigger an [Automation](https://www.airship.com/docs/reference/glossary/#automation) or [Sequence](https://www.airship.com/docs/reference/glossary/#sequence) when a user opts in to or out of a subscription, or use their opt-in status as a [Condition](https://www.airship.com/docs/reference/glossary/#conditions_event_option). See: * [Subscription](https://www.airship.com/docs/guides/messaging/messages/sequences/triggers/#subscription) in *Automation and Sequence Triggers* * [Conditions](https://www.airship.com/docs/guides/messaging/messages/sequences/create-automation/#conditions) in the Setup section of *Create an Automation* * [Conditions](https://www.airship.com/docs/guides/messaging/messages/sequences/create/add-messages/#conditions) in *Add Messages to a Sequence* * **Segments** — Include a subscription list in a [Segment](https://www.airship.com/docs/reference/glossary/#segment). For the API, see the [`/api/segments` endpoint](https://www.airship.com/docs/developer/rest-api/ua/operations/segments/). * **Preference centers** — Add subscription lists to [Preference Centers](https://www.airship.com/docs/reference/glossary/#preference_center). * **SMS keywords** — Set up [keywords](https://www.airship.com/docs/guides/messaging/features/sms-keywords/) your audience can use to opt in to or out of your subscription lists. Once added to your project, you can include the keywords in your SMS messages. ## Managing subscription lists Go to *Audience » Lists » Subscription*. The default sort order is by last modified. Each row displays: * List name and ID * Type — *Commercial* or *Transactional*, and *Auto opt-in*, if enabled * Channels * Description * Date and time last modified (browser local time) * Audience count — The number of [Channel IDs](https://www.airship.com/docs/reference/glossary/#channel_id) in the list and the time it was last calculated (browser local time). Click to generate an updated count. Lists for all channels appear by default. Click *All channels * and select a channel to filter for only lists enabled for that channel. You can search for lists by name, ID, or description. Click to view a list's reporting data. Click to edit a list's name, type, description, or enabled channels. Click to archive.