How to fill in a PDF form on your computer or phone

PDF forms come in two kinds, and knowing which one you have saves a lot of frustration.

Fillable forms

A fillable form has real fields built in: text boxes, checkboxes and drop-down menus. Government agencies, banks and insurers usually publish forms this way. When you open one in Fill PDF form, every field is highlighted, and you can click into it and type.

1. Add the form.
2. Select each highlighted field and fill it in. Press Tab to jump to the next field.
3. Tick checkboxes and choose from drop-downs where they appear.
4. Select Save filled PDF.

Your answers are saved into the form’s own fields, so the person you send it to sees them in any PDF reader.

Flat forms

A flat form is just a picture of a paper form, often a scan, with no fields. Nothing will highlight, and you can’t click into the boxes. You can still fill it in without printing it: open Sign PDF, choose Add text, and place text wherever you need it. Drag each piece onto the right line and resize it to match.

Should you lock your answers?

Fill PDF form has an option to lock answers, also called flattening. It turns your answers into part of the page, so they can no longer be edited.

• Lock when you’re submitting a finished form, so nothing changes by accident on the way.
• Don’t lock if someone else still needs to add to the form, such as a manager signing off or an office adding a reference number.

Common problems

• The form opens but shows a message about needing Adobe Reader. Some older government forms use a format called XFA that only Adobe’s software can fill. Check whether the agency offers a newer version, or use Adobe Reader for that one form.
• Accented or non-English characters don’t appear. Some forms only include fonts for basic Latin characters. If a character won’t show, try typing it without the accent, or ask the organisation for a different version of the form.
• The text is tiny or overflows. The form’s designer set the field size. Keep answers short, or use the form’s notes section if there is one.

More guides

• How to make a PDF small enough to emailMost email services won’t send attachments over about 20–25 MB. Here’s how to get a PDF under the limit without wrecking it.
• Are online PDF tools safe to use?Most online PDF tools upload your file to a company’s server. Here’s what that means, and how to choose a tool you can trust with private documents.
• How to sign a PDF without printing itPrint, sign, scan, email: there’s a faster way. Here’s how to sign a PDF on your computer or phone, and when an electronic signature is enough.
• How to password-protect a PDFA password stops anyone without it from opening your PDF. Here’s how to add one properly, and how to share the password without undoing the point.