How to fill in a PDF form
Fillable forms, flat forms that only look fillable, and locking your answers.
Application forms, tax forms, registration forms and HR paperwork often arrive as PDFs. Some are designed to be filled in on screen, some only look like it. Knowing which you have saves a lot of frustration.
Is the form fillable?
A fillable PDF has real form fields: boxes you can click and type into, tick boxes, drop-down lists and radio buttons. A flat PDF only shows the lines and boxes as printed graphics. The quickest test is to drop it into the Edit PDF tool: it lists every real form field it finds. If the list is empty, the form is flat.
Filling in a fillable form
- Drop the PDF into the Edit PDF tool.
- In the Form fields section, type your answers. Tick boxes, radio buttons and drop-downs work as you would expect.
- Add a signature if the form needs one, by drawing or uploading it and clicking where it goes.
- Choose whether to keep the fields editable or lock them, then save.
Field names come from whoever made the form and are sometimes cryptic, such as Text12. The field order usually follows the page, so work through them in sequence and check the result.
Keep editable or lock?
| Choose | When |
|---|---|
| Keep editable | You are pre-filling a form that someone else will complete, or you may need to correct it later |
| Lock values | You are submitting the final form, especially with a signature, and it should not be altered |
Locking, also called flattening, turns your answers into part of the page. They look the same, but the fields disappear, so nobody can change them quietly after you send it.
When the form is not fillable
A flat PDF form has no fields to fill. Your options:
- Ask for a fillable version. Many organisations have one and simply sent the wrong file.
- Print, fill in by hand, and scan. Then combine the scans into one PDF with images to PDF and shrink it with the PDF compressor before sending.
- Use a full PDF editor that can place text boxes anywhere on a page.
On a phone
The Edit PDF tool works in phone browsers too. For forms with a lot of typing, a computer is easier, but for signing and ticking a few boxes a phone is fine.
Privacy
Forms are full of personal details. Filling them in your browser means the completed form exists only on your device until you choose to send it.