Contact fields and personalization

Every contact has standard fields: email, first name, last name, full name and language. Custom fields add your own data.

1. Go to Contact fields.
2. In the New field form, give it a Label (what you see) and a Key (what you type in tags and the API).
3. Pick a Type, then add a Default value if you want one.
4. Click Add field.

To change one contact's values, open the contact from the Audience list.

• Text: up to 1,000 characters.
• Number: 12, 1 234,5 or 1,234.5 all work in a CSV.
• Date: written YYYY-MM-DD, like 2026-10-22.
• Yes / no: in a CSV, yes, oui, true or 1 mean yes; no, non, false or 0 mean no.
• Choice: 1 to 50 options, one per line. A CSV value matches an option even with different capital letters.

A workspace can have up to 50 fields. A key starts with a lowercase letter, then uses lowercase letters, digits or _, up to 40 characters. Names used by the app, like email or status, are not allowed.

The key and the type can't change after creation. Deleting a field also deletes its values on every contact.

Turn on Offered in signup forms to let new subscribers fill a field when they sign up. Forms can only write fields that have this on.

A tag is replaced by each subscriber's value when the email is sent. Tags work in the subject, the preheader and the body.

{{first_name}}
{{last_name}}
{{name}}
{{email}}
{{language}}
{{custom.plan}}

Use custom. followed by the key for your own fields. Spaces inside the braces are fine: {{ first_name }}.

In the visual editor, type / and pick a Variable entry. You can add the text to show when the value is empty.

If a contact has no first name but has a full name, {{first_name}} uses the first word of the full name.

Add filters after a | sign. There are four:

• default: "text": shows this text when the value is empty. Up to 200 characters. Single or double quotes both work.
• upper: all capital letters.
• lower: all small letters.
• capitalize: a capital first letter. The rest stays as it is.

Hi {{first_name | default: "there"}}
=> Hi Anna  (or "Hi there" when the first name is empty)

{{first_name | default: "friend" | capitalize}}
=> anna becomes Anna, empty becomes Friend

{{custom.city | upper}}
=> lyon becomes LYON

Filters run from left to right. So {{first_name | upper | default: "there"}} shows there in small letters when the name is empty.

A custom field's default value is used when the contact has no value. A default: filter in the tag is used when both are empty.

• A tag with a typo, an unknown field or an unknown filter is left exactly as typed. Check your test email.
• On the public archive page of an issue, every tag shows its fallback, or nothing. A visitor never sees a subscriber's data.
• Before sending, the last check warns you when a tag without a fallback would be empty for many subscribers.
• A value is cut after 1,000 characters. Line breaks are removed in the subject.