How to fill in a PDF form that won’t let you type

Three things are all called “a PDF form”

1. An AcroForm — a real, interactive form

The document contains proper interactive fields: text boxes, tick boxes, dropdowns, radio buttons. Tab moves between them. This is the normal case and almost every PDF reader made in the last fifteen years can fill one in, Emifyn PDF Studio included.

If the fields exist but refuse you, the usual causes are a permissions password restricting form filling, fields deliberately marked read-only by whoever made the form, or a reader that is opening the document in a limited preview mode. Browsers and email clients are frequent culprits here — download the file and open it properly before concluding anything.

2. A flat form — a picture of a form

Very common. Somebody designed the form in Word, exported it to PDF, and never added any fields; or it was printed, filled in by hand once, scanned, and passed around ever since. There is nothing to click because there is nothing there.

You fill this in by adding text on top of the page. Any tool that can add a text box will do, and this is the one job where the free browser tools are genuinely fine — though if the form contains anything personal, think about whether you want to upload it.

3. An XFA form

Adobe introduced XFA as a way of building forms that could change as you filled them in, with the actual form defined in XML rather than as a PDF page. It never became a widely-supported standard and Adobe itself has moved away from it, but the files linger — you will still meet them from some government departments, banks and insurers.

A non-Adobe reader will usually show a grey placeholder page. This is not a fault in the reader; the page genuinely has nothing on it, because the real form is in the XML. Your options are to open it in Adobe Acrobat Reader, which is free, or to go back to the organisation and ask for an ordinary PDF or a web form. There is no clever workaround here and anyone claiming otherwise is selling something.

Filling in a flat form, properly

1. Zoom in first. Getting the text on the line rather than near it is most of the job, and it is much easier at 150% than at page-fit.

2. Add a text box on the line. Place it, type, and set the size so it sits on the rule rather than floating above or crashing through it.

3. Match the form’s type, roughly. A serif form filled in with Arial looks like a form filled in by a computer. That may be exactly what you want. If you would rather it looked handwritten, most people are better served by printing it.

4. Tick boxes are a character, not a drawing. An X in a text box is neater, straighter and more legible than a hand-drawn cross, and it reproduces properly when the form is printed at the other end.

5. Signatures. Sign a blank sheet of white paper, photograph it, crop it tight, and drop it in as an image. Keep that file somewhere private — it is your signature.

6. Print to check. Forms exist to be printed. Print a copy, or at least use print preview, and make sure nothing you added sits outside the printable area.

Before you send it back

• Flatten it if you can. Flattening turns your entries into part of the page so they cannot be dragged around, deleted or accidentally cleared by the recipient’s software. Some readers reset unsaved form fields; flattening puts an end to that.
• Save, then reopen, then look. The most common way a completed form arrives blank is that the sender’s reader never committed the fields to the file.
• Check what else is in the file. If you filled in a form that someone else had already used, their entries may still be in there. So might the metadata. See redacting a PDF.
• Do not email a filled form with your bank details to an address you did not verify. Worth saying plainly, because forms are exactly what this kind of fraud runs on.