Fill a PDF form

Because a lot of forms aren't forms. They're a scanned or printed-looking page with lines drawn on it, and there are no fields to type into. The document looks identical either way, which is why this is confusing.

A real form has fields the author created. Click one and a cursor appears. A picture of a form has nothing to click.

Telling which you have

Open it here. If fields appear, it's a real form and you can fill them in. If you're told there are none, it's a picture.

The other quick test in any PDF reader: press Tab. In a real form, focus jumps between fields. In a picture, nothing happens.

If it's a picture

You need to place text on top rather than type into anything. Printing it, filling it by hand and scanning it back is the honest fallback, and for a lot of official forms it's what the recipient expects anyway.

If it has to stay digital, signing tools will place an image on the page, which covers a signature but not thirty fields of text.

Worth checking before you resort to that: many organisations publish both a flat version for printing and a fillable one, and the fillable one is often one click away on the same page.

Flattening, and when not to

Flattening turns your answers into part of the page. They stop being form values and become drawn text.

Flatten when the form is finished. It stops anyone changing the answers, stops a reader with different default settings showing them differently, and guarantees they print. A filled form that isn't flattened can reach somebody whose software shows the fields empty, which happens more than you'd expect with forms opened in a browser's built-in reader.

Don't flatten when the form is going to somebody else to complete. They'll have nothing to type into.

The default here is to flatten, because most people filling a form are finishing it rather than passing it on.

Flattening can't be undone. If you might need to change an answer, keep the unflattened copy.

Field types

Text fields hold whatever you type, and some have a maximum length set by the author. If typing stops at a certain point, that's why.

Checkboxes are on or off. Some forms use a group of checkboxes where the author meant them to be exclusive and didn't set them up that way, so more than one can be ticked. That's the form's fault, not yours, but the recipient will still see it.

Dropdowns and radio groups only accept the options the author defined. There's no way to enter something not on the list.

Field names are shown as the labels here, and they come from whatever the author called them. Well made forms have names like applicant.surname. Badly made ones have Text12, and matching those to the visible labels means looking at the form as well.

Calculations and validation

Some forms carry scripts that add up totals or check a date is valid. Those scripts don't run here, so a total field stays empty and a date that should be rejected isn't.

If a form has a calculated total, work it out and type it in, then check it against what the form expects. Submitting a form with an empty total is a common reason for one coming back.

Before you send it

Open the result and read it. Not the form, the result. It's the quickest way to catch a field that didn't take what you thought it did, and it catches flattening applied when it shouldn't have been.

If the form also needs signing, fill it in first and sign afterwards. Signing first and filling second means the answers can still be altered while your signature sits under them implying otherwise.

Nothing is uploaded. The form is read and written in your browser, which matters because these are usually applications, claims and tax documents.