Drag & drop the PDF you want to make fillable. In the Annotate tab, Click “Add text box”. Click where you want to insert a form field and type your placeholder text. Add an underline or box to create empty fields to fill out (see below).
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.
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.