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What is a subform?

A subform is a form within a main form that lets you collect related information in a structured way. Subforms are useful when you need to add multiple entries or records while keeping everything connected in one place. Common use cases include:
  • Collecting multiple products in an order
  • Adding a list of expenses to a report
  • Creating a list of tasks for a project
Respondent filling in a subform entry with a full name and age, then submitting it

How to use a subform within your form

1

Create the form for your subform

A subform is a separate form that opens as a popup in your main form. First, create a form with the questions you want to ask for each entry, like any other form. Then click Publish.
You can’t create the subform from inside the main form. Only published forms show up when you link one.
2

Add a subform field

In the left-hand panel of your form, click Subform. Then type the question or information you need from your respondents.
Form editor with a Subform field labelled Dependents and an Add dependent button
3

Link forms

Click the field’s settings icon to open the right-hand panel. Under Connected subform, choose the form you created. The list shows published forms you can edit.Then, pick a Main field: the subform question whose answer labels each entry. If you don’t pick one, each entry shows the Submission text from the Appearance settings.To change the subform’s questions later, click Edit form under Connected subform. Then publish the subform itself. Publishing the main form doesn’t update it.If you duplicate the main form, the subform field in the copy isn’t linked to any form. Open the copy, choose the subform again under Connected subform, then choose its Main field.
Subform settings with Connected subform, Edit form and Main field
Forms in the Trash aren’t listed. An existing subform whose linked form was moved to the Trash will show Select form until that form is restored.
4

Publish and share

Publish your form and share the link. Subforms allow respondents to edit completed submissions and resume partial ones.A subform only lists the entries the respondent created during their current visit, and they can edit those. Entries from other visits or other respondents don’t show.
A live form with four completed subform entries, each with Edit, and an Add dependent button

How subform entries are saved

Each entry is a submission of the subform’s own form:
  • When a respondent submits an entry in the popup, it’s saved right away in the subform’s Results, even if they never submit the main form.
  • If they close the popup before submitting, the entry is saved as in progress.
  • Subforms the respondent never opens save nothing.
On the review page, each entry shows its Main field. If you didn’t pick one, it shows your Submission text, like Submission chosen. Emails don’t list the entries. In the respondent’s copy of their answers, the subform field shows Answered. In your self-email notification, it shows View in Fillout. Open the submission in Results to see each entry.

Use subform answers in the main form

Type @ in the main form to reference answers from the subform, like in a calculation or an email. You can reference most question types, including text, email, phone, number, choice, rating, date and address fields. You can’t reference signatures, file uploads or tables. Webhooks and the Fillout REST API send each subform entry as a full submission inside the main submission, with up to 50 entries per subform field. Older forms may send subform entries in a simpler format.

Add subform limits

Under Validation in the right-hand panel, you can:
  • Turn on Require minimum submissions and set Minimum submissions
  • Turn on Limit maximum submissions and set Maximum submissions
  • Add an Error message
The minimum and maximum are fixed numbers. They can’t come from an answer, a calculation or a URL parameter. Each finished entry also counts toward the subform’s own submission limit. If that form reaches its limit, respondents can’t add more entries. To rename the button respondents click to add an entry, change Button text under Appearance. It says Create by default. For example, change it to Add another attendee.
Subform Validation settings with Require minimum submissions, Limit maximum submissions and Error message

Subform field vs record picker subform

Fillout has two kinds of subform. A Subform field adds entries to another Fillout form. A record picker subform creates or edits linked records in your database. To add repeated entries that live in another Fillout form, use a Subform field. To create or edit linked records in your database, or show existing ones, use a record picker.

Select from previous submissions

You can also allow respondents to pre-fill form fields with existing form records by adding a Submission picker field. Learn how in Submission picker.

Submission picker

Let respondents pre-fill forms with answers from existing forms.

Get multiple answers

Let respondents enter multiple sets of data for one question.