Pre-populate invite fields

Save time for clients by pre-populating their info on your invites. You can pre-populate every field on the invite page including name, email, and custom questions.

Pre-populated fields are set by passing query parameters in the invite URL. Here's an example URL:

https://zcal.co/i/12345678/?startDate=2026-01-01T18%3A30%3A00.000Z&timezone=America%2FLos_Angeles&name=John%20Smith&[email protected]&a0=Q1&a1=Q2&a2=Option+1&a3=Option+1,Option+2&a4=Option+1&a5=%2B15555555555&[email protected],[email protected]&locationIndex=1&smsPhone=%2B15555555555&duration=60

Add query parameters to your invite link

1) Copy the link for the invite you want to share

2) If your link doesn’t already have a query parameter add "?" to the end of the link. If there's already a query parameter in your link, continue to step 4.

3) Add a property name (the field name) followed by the user's information (the field value). To add space between words, enter "%20".

4) To add variables to your link, enter "&" then add more query parameters per step 3.

Note: invalid query parameters will be ignored.

Query parameter reference

Here is a list of the query parameters you can add to your invite link.

startDate

The date and ISO time to pre-fill.

Example: startDate=2026-01-01T18%3A30%3A00.000Z

timezone

The IANA timezone to pre-fill.

Example: timezone=America%2FLos_Angeles

name

The invitee's name.

Example: name=John%20Doe

email

The invitee's email.

Example: [email protected]

a[custom question index]

Answer to a custom question. Each custom question has its own query parameter and question indices start from 0.

Freeform custom questions e.g. Short text can accept any string as a value

Example: a0=Q1

Multiple choice custom questions e.g. Dropdown can only accept strings that match one of the provided options.

Example: a2=Option+1

Checkbox custom questions can accept multiple comma-separated string values, all of which must match the provided options.

Example: a3=Option+1,Option+2

Phone number custom question responses must start with a valid country code.

Example: a5=%2B15555555555

guests

Guest emails. Separate with commas if there are multiple guests.

Example: [email protected],[email protected]

locationIndex

If your invite has multiple location options, you can pre-select a location by index. Indices start from 0.

Example: locationIndex=1

duration

If your invite has multiple duration options, you can pre-select a duration by value.

Example: duration=60

smsPhone

If your invite has SMS reminders enabled, you can set a phone number starting with a valid country code.

Example:smsPhone=%2B15555555555