How to fill in interactive PDF forms

▶ 1. Two kinds of form, two routes

First of all it helps to work out which of the two cases you are dealing with, because the method changes.

• ✓ Interactive form: clicking a box brings up a cursor and you can type. The fields already exist inside the PDF and only need filling.
• ✓ Flat PDF: the form is just the image or the text of a sheet, with no fields. Clicking does nothing: you will have to add the text or create the fields yourself.

With 123 PDF Editor PRO you handle both cases in the same place, straight in the browser: no desktop software to install and no uploading of the document — which matters, since forms almost always contain personal data.

▤ 2. Filling in a form that is already interactive

This is the simplest case: the fields are there, you just fill them in and download the document.

1. Install the extension from the download page and click its icon in the toolbar.
2. Click Choose a PDF (or Open PDF) and select the form to fill in.
3. Open Fill form and type directly into the fields already present in the document.
4. Move from one field to the next, completing all the required information.
5. Click Download PDF to save the completed form.

＋ 3. If the PDF has no fillable fields

When the form is flat and you only need to hand it in completed, the quickest route is to write over the document with a text box.

1. From the Insert bar choose Add text.
2. Draw a box over the line to be filled in and type the content.
3. Adjust font, size and colour so the text blends with the printed form.
4. Repeat for every entry and, if you need a tick, use Add text with a character such as “X”, or a shape from Annotations and comments.

◆ 4. Creating fillable fields to distribute

If instead you are the one who needs others to fill the form in, you can turn a static PDF into a genuinely interactive form: the fields keep working in the downloaded file.

1. Open Create form and choose the field type: text, multiline text, checkbox, radio button, dropdown, list box or button.
2. Drag a rectangle on the page to place the field in the right spot.
3. Set the field name, the default value, colours and border.
4. Switch on the useful options: Required to make it mandatory, Read only for pre-filled fields that must not be changed.
5. For buttons you can define actions such as opening a link, going to a page, submitting or resetting the form.
6. Download the PDF: whoever receives it will be able to fill it in with any compatible reader.

✎ 5. Signing the form

Many forms have to be handed in signed. There are two options, depending on how formal the signature has to be.

1. Image signature: open Add signature, upload a PNG or JPG of your signature (a transparent PNG works best), select it and click Place selected signature.
2. Digital signature: open Digital signature, choose a .p12/.pfx certificate, enter its password and complete the details; then click Digitally sign and download.

⤓ 6. Saving, protecting and sending

Before sending the completed form off, it can be useful to lock it or make it lighter.

1. Click Download PDF to get the completed form.
2. If it contains sensitive data, open Password protection and protect it with a password (AES-256 encryption), deciding in Allowed actions what the recipient may do.
3. If the attachment is too heavy, follow the guide on how to compress a PDF.

? 7. Frequently asked questions

The questions that come up most often on this topic.