Why is my PDF fillable form not editable? If PDF filling form fields not allowed, this could be due to a corrupted document, PDF form filling restriction, and document protection. Additionally, the security restrictions imposed by creators unable users to edit the PDF form with ease.
Make sure that the security settings allow form filling. (See File > Properties > Security.) Make sure that the PDF includes interactive, or fillable, form fields. Sometimes form creators forget to convert their PDFs to interactive forms, or they intentionally design a form you can only fill in by hand.
Create a Form Place the text cursor where you want to insert the form field. Click the Developer tab on the ribbon. Click the Design Mode button in the controls group. Click a Content Control buttons to insert the selected type of control. When you're done, click the Design Mode button again to exit Design Mode.