Quick summary

Custom contact attributes store extra information about your contacts, beyond the standard attributes - for example, membership status, customer type, or renewal links.
Choose a data type when you create the attribute: single choice, multiple choice, true/false, date, or number.
Add values to your contacts via CSV import, signup forms, or integrations.
Use attributes to filter your audience, build segments, and personalize emails with merge tags.

Create a custom contact attribute

Click your organization name in the top-right corner and go to Settings → Custom attributes
Click Create attribute
Fill in the fields below

Name

Choose a short, clear name that describes what the attribute stores.

Description (optional)

Add a description so your team knows when and how to use this attribute.

Data type

Choose the data type based on how you plan to work with the attribute in MarketHype.

⚠️ Important: The data type cannot be changed later.

Data type	How it works	Example
Single choice	Each contact can have one value for this attribute. Importing a new value will replace the previous value.	Attribute: “Customer type” Value: “Gold customer” If the same contact is later imported with “Silver customer”, it overrides the previous value.
Multiple choice	Each contact can have multiple values for this attribute.	Attribute: “Customer type” Values: “Gold customer” and “Silver customer” can both be linked to the same contact.
True/False	A yes/no (boolean) attribute. Supported values are `true` or `false`.	Attribute: “Member” Value: true
Date	A date value in `YYYY-MM-DD` format.	Attribute: “Date of arrangement” Value: 2027-05-30
Number	A numeric value.	Attribute: “Year of arrangement” Value: 2027

ℹ️ Note: For long identifiers like organization numbers, we recommend using the Single choice data type rather than Number. These values can exceed what the Number type is able to store, so they won't be saved correctly.

💡 Tip: Use the Single choice data type when importing values like renewal or payment links that you want to insert as merge tags in emails. See our help article on sending emails with renewal links.

Edit custom attributes

Click your organization name in the top-right corner and go to Settings → Custom attributes
Hover over the attribute
Click Edit
Update the name or description.

The data type cannot be modified.

Delete a custom attribute

Click your organization name in the top-right corner and go to Settings → Custom attributes
Hover over the attribute
Click Edit
Click Delete

⚠️ Important: Deleting an attribute removes all contact data saved for that attribute. This cannot be undone.

Use custom attributes

To use an attribute, first add values to your contacts in one of these ways:

CSV import: Learn more about importing contacts here.
Signup forms: Collect values when contacts sign up. Learn more about creating a signup form with custom attributes here.
Integrations: Requires developer setup. Learn more in our developer documentation.

Once the attribute is added to contacts, you can use it in different parts of MarketHype:

Audience filters: Find attributes under Include/Exclude → Contact attribute and use them when filtering your audience, creating segments, or sending emails.
Merge tags in emails: Attributes with the data type Single choice can be used as merge tags in emails (Merge tags → Person). Learn more about merge tags here.

How to: Manage custom contact attributes