How to Pre-Fill Registration Form Fields Using a URL

Eventact lets you pass values directly to registration form fields through the registration URL. When an attendee opens the link, the specified field is automatically populated or selected.

This is particularly useful when linking an external pricing, ticket, partner, or campaign page directly to an Eventact registration form.

Common Use Cases

Pre-Select a Ticket or Registration Type

If your website has a separate pricing or ticket page, create a different registration link for each option.

For example, an attendee who clicks Register for VIP can arrive at the Eventact registration form with the VIP registration type already selected. This avoids asking attendees to make the same selection twice.

Pre-Fill Promo or Discount Codes

Create links that automatically populate a promotion or discount code.

You can distribute these links to members, partners, sponsors, invited groups, or other eligible audiences.

Pass Partner or Group Information

Automatically populate values such as a partner ID, company code, member reference, or group identifier instead of asking attendees to enter the information manually.

Note: For marketing campaign attribution, use standard UTM parameters such as utm_source, utm_medium, and utm_campaign when appropriate.

How to Set Up a Pre-Filled Registration URL

1. Create or Identify the Field: Select the registration form field you want to pre-fill.
2. Find the Field ID: Locate the field's unique numeric ID - for example, 199996.
3. Copy the Registration Form URL: Start with your registration form URL. For example:
   https://reg.eventact.com/welcome?Form=888&c=999&Event=777&lang=en
4. Add the Pre-Fill Parameter: Append &d=[Field ID],[Value] to the URL.
   For example, to populate field 199996 with the value 16:
   https://reg.eventact.com/welcome?Form=888&c=999&Event=777&lang=en&d=199996,16
5. Test and Publish: Open the completed URL and verify that the correct value is populated or selected. Once tested, you can publish or distribute the link.

How It Works

Eventact uses the d URL parameter to pass a value to a registration form field.

The format is: &d=[Field ID],[Value]

For example:

https://reg.eventact.com/welcome?Form=ikHw&c=i4wI&Event=icX8&lang=en&d=199996,16

URL Breakdown

• Base registration URL: https://reg.eventact.com/welcome?Form=ikHw&c=i4wI&Event=icX8&lang=en
• Pre-fill parameter: &d=199996,16

Where:

• d tells Eventact to pass data to a registration field.
• 199996 is the unique Field ID.
• 16 is the value assigned to that field.

How to Find the Field ID

1. Open the registration form in the Eventact form builder.
2. Select the field you want to pre-fill.
3. Open the field's properties.
4. Expand the Data section.
5. Locate the unique numeric Field ID.

Use this ID when constructing the URL.

Using Different Field Types

The value you pass must match the type of field you are targeting.

Text and Number Fields

Pass the value you want Eventact to insert into the field.

Dropdowns and Radio Buttons

Use the option's internal value rather than the text displayed to attendees.

For example, if attendees see VIP Registration but the option's internal value is 16, use 16 in the URL.

Checkboxes

• Use 1 to select the checkbox.
• Use 0 to leave it unselected.

Values with Spaces or Special Characters

If a value contains spaces or special characters, URL-encode it. For example, a space can be represented as %20.

Always test the final URL before distributing it.

Practical Examples

Link from an External Ticket Page

Your event website may display several registration options, such as Standard, Premium, and VIP.

Instead of sending all buttons to the same generic registration starting point, each button can contain the appropriate Eventact field value. The attendee arrives at the registration form with the option they already selected pre-filled.

Partner-Specific Registration Link

Create a dedicated registration link for a partner or organization that automatically populates its partner code.

The attendee doesn't need to know or manually enter the code.

Promotion Link

Send eligible attendees a link that automatically populates the relevant promotion code, reducing another manual step in the registration process.

QR Codes

You can also convert the completed URL into a QR code for use on posters, banners, invitations, or other materials.

When attendees scan the QR code, they open the Eventact registration form with the specified value already populated.

What's Next?

• Build & Test: Construct your pre-filled URLs and test them in a private/incognito window to ensure values populate correctly.
• Explore More Guides: For additional tutorials and best practices, check out the Eventact Pro guides.
• Need Assistance? If you need help configuring your registration flow or setting up custom URLs, contact Eventact Support.