interactive pdf with mandatory fields?

For what purpose: Saving the file? Printing it? Submitting it? Something else?

And what should happen if they don't fill them all in?

Hi Julie

Hope you are doing well and thanks for reaching out. As described you want to make the form field mandatory for the user when filling the form.

Please use the steps below to make a field mandatory for the user:

1. Open the PDF form > Go to Tools > Prepare Form

2. Right click on a form field > Select 'Set as required field'

3. Save the changes to the PDF, once set up the required fields will be highlighted in red and the user wont be able to submit the form  until all the required fields are filled out.

Regards

Amal