--- schema_version: "1" id: 47ddc36d067ede7426461032ea7eb824ee6ba855a3790d09ee747047afdc6249 title: Create a Data Extension in Email Studio collection: admin version: current locale: en-us portal_url: https://docs.salesforce.com/admin/current/en-us/mktg/264-0-0/mc_es_create_data_extension.md canonical_url: https://help.salesforce.com/s/articleView?id=mktg.mc_es_create_data_extension.htm&release=264.0.0&type=5 source_site: help.salesforce.com content_type: documentation content_hash: 3e193f18000df44cba5614b8c8c401f146e853740ce5553c25d15962a8781694 description: A data extension is a table that contains data that you provide. Use data extensions to hold customer data, track loyalty points, collect tracking and usage data, and many more use cases that require you to store information in a table. products: - Marketing - Marketing Cloud Engagement release: "264" --- # Create a Data Extension in Email Studio A data extension is a table that contains data that you provide. Use data extensions to hold customer data, track loyalty points, collect tracking and usage data, and many more use cases that require you to store information in a table. - **[Manage Policies for an Email Studio Data Extension](https://help.salesforce.com/s/articleView?id=mktg.mc_es_manage_de_policies.htm&release=264.0.0&type=5)** If you have this feature enabled in Email Studio, the admin user for your account can allow or disallow users to delete a data extension, modify existing fields in a data extension, or add more fields to a data extension. Even if a user’s permission allows them to delete or update data extensions, the change control policy takes precedence over their permissions. If all users permissions for the account are set to deny for deleting data extension and deny for updating a data extension, the change control policy doesn’t need to be configured. Contact your account administrator if you would like to activate this feature. ## Step 1: Specify the Data Extension Properties ![Note](https://sf-zdocs-cdn-prod.zoominsoftware.com/tdta-mktg-mc_email-264-0-0-production-enus/a0b807ef-dfbb-412c-b26e-310d91f2d6df/images/icon_note.png) Note A data extension field name can include only alphanumeric characters, spaces, dashes, underscores, and periods. 1. In Email Studio, select **Subscribers** | **Data Extensions**. 2. Click **Create**. 3. Select **Standard Data Extension**. 4. On the Properties page, for Creation Method, select **Create from New**. 5. Specify the properties of the data extension. 1. Enter a name for the data extension. 2. Enter a unique external key to identify the data extension. If you don’t specify an external key, a unique key is created for you. You use this key to refer to the data extension in API calls, AMPscript functions, and SSJS functions. 3. Enter a description of the data extension. 4. For Location, choose a folder to store the data extension in. 5. To make the data extension eligible for message sends, select **Is Sendable**. 6. To make the data extension eligible for test sends, select **Is Testable**. 6. Click **Next**. ## (Optional) Step 2: Define the Data Retention Policy 1. To enable a data retention policy, turn on **Retention Setting**. Otherwise, click **Next**. 2. If you enabled data retention, select which records to delete in the data extension at the end of the retention period.

Individual Records	Individual records are deleted based on their creation dates, but the data extension isn’t deleted.
All records and data extensions	Both the data extension and the records inside of it are deleted.
All records	All the records in the data extension are deleted, but the data extension isn’t deleted.

3. Specify the time period for the retention policy. You can select a specific date or a time period, such as 3 months or 7 days. 4. Click **Next**. ## Step 3: Define the Fields ![Note](https://sf-zdocs-cdn-prod.zoominsoftware.com/tdta-mktg-mc_email-264-0-0-production-enus/a0b807ef-dfbb-412c-b26e-310d91f2d6df/images/icon_note.png) Note A data extension field name can include only alphanumeric characters, spaces, dashes, underscores, and periods. 1. In the Name column, enter a unique name for the field in the data extension. 2. Select the [type of data](https://help.salesforce.com/s/articleView?id=mktg.mc_es_data_extension_data_types.htm&release=264.0.0&type=5 "When you create a column in a data extension in Marketing Cloud Engagement, select one of these data types.") that the field contains.

Text	A string of text that can contain letters, numbers, and spaces.
Number	An integer.
Date	A system date. Times are stored in Central Standard Time. Dates are stored in the format MM/DD/YYYY.
Boolean	A true or false value.
EmailAddress	An email address. This field must be present to send an email to the data extension.
Phone	A phone number. Characters that aren’t digits are removed.
Decimal	A number with a decimal point. You must specify two Length properties for decimal values. The first property is the total length of the value, and the second is the number of digits that follow the decimal point. For example, if you set the Length value to `7,2`, the number `12345.67` is valid, but `987654.321` isn’t.
Locale	A locale code. For a list of accepted values, see Valid Locales for Data Extension Sends.

3. For Length, enter the maximum number of characters that the field can contain. You can specify a maximum length only for the Text and Decimal data types. 4. To use the value of the field to identify unique records, select **Primary Key**. Primary key values can't exceed 850 characters. Each primary key value in the data extension must be unique. After you create a data extension, you can’t modify the primary key fields. We suggest including no more than 3 columns as primary keys. 5. To require the field to contain a value, select **Nullable**. 6. To use a default value for the field if none is provided, enter the value in Default Value. 7. To encrypt the contents of the field, select **Encrypt Field**. This option is available only for accounts with [field-level encryption](https://help.salesforce.com/s/articleView?id=mktg.mc_overview_field_level_encryption.htm&language=en_US) enabled. For more information about field-level encryption, contact your account executive. 8. Repeat these steps for each field that you want to add to the data extension. 9. If the data extension is sendable, specify how the data in the data extension is related to subscriber data. 1. Next to Send Relationship, from the left dropdown menu, select a data extension field that corresponds to a subscriber value. 2. From the dropdown menu on the right, select whether the field corresponds to the subscriber key or the subscriber ID. 10. Click **Create**.