Custom subscriber fields

What custom fields are for

Custom fields let you attach extra data to each subscriber beyond their email and name. Anything you know about a contact — their company, subscription plan, a signup date, a preferred language — can become a field. Once stored, you can use those values as merge tags inside email content (so each subscriber sees their own data), and as filter conditions when building segments.

Create a custom field

1. Go to Newsletter → Subscribers → Fields tab.
2. Click Add field.
3. Fill in the field name (shown in the UI and subscriber profile), the field type, and the tag.
4. Click Save.

Field types

Type	Use for
Text	Any string value — company name, country code, plan tier
Number	Integer or decimal — account ID, revenue, seat count
Date	Calendar date (no time component) — trial expiry, signup date, birthday
Datetime	Date + time — last login timestamp, exact subscription time

Tags and merge tags

The tag is the short variable name you use to reference the field in email content. A field named "Company name" with tag company is inserted in the email editor as {{company}} (no spaces — that's what the editor's insert button produces). When the email is sent, Yaplet replaces the tag with each subscriber's stored value for that field.

The following tags are reserved by Yaplet and cannot be used for custom fields:

• email
• name
• created_at
• state
• subscribeURL
• unsubscribeURL

Set field values on subscribers

You can populate custom field values in several ways:

• CSV import — add the field tag as a column header in your CSV file. Yaplet maps the column to the matching field during import.
• API bulk upsert — include a fields object keyed by tag in each contact record in the JSON payload.
• Edit a subscriber — click a subscriber's email in the list to open their profile, then edit field values directly.

Use custom fields in segments

Custom fields appear as filter options in the segment builder. Depending on the field type, you can filter by text match, numeric range, or date comparison — for example, plan equals pro or trial_expiry is before today.

Rename or delete a field

On the Fields tab, click the pencil icon in the row's actions to rename a field. The name cell itself is plain text and does not respond to clicks.

Warning — renaming changes both the display name and the tag. The rename modal exposes two inputs (Name and Tag) and writes both to the database. Changing the tag silently breaks every email body, segment filter, and CSV header that referenced the old tag, and existing subscriber values stay under the old key inside the JSONB column — they will not appear under the new tag. Only change the tag right after creating the field, before any subscriber data is stored against it. If you need to rename a tag that already has data, create a new field with the new tag and migrate the values manually.

To remove a field entirely, click Delete. Deleting a field removes all stored values for that field from every subscriber record.

What's next

Put your fields to work: build a segment that targets subscribers by field value, or open the email editor to add personalized merge tags to your next campaign.