How to fill out and sign a PDF on iPhone

A form lands in your email while you are out. It needs your answers, your signature and the date, and it has to go back today. You do not need a printer, a scanner or a laptop. Your phone can do all of it.

This guide goes from the first tap to the sent email, with the small things that trip people up on a phone screen: tiny boxes, a keyboard in the way and a signature that comes out shaky.

How do I fill out and sign a PDF on my iPhone?

Open Fill and Sign PDF in your phone's browser, add the form, fill it in, sign it and send it. It all happens in your browser, so the form is not uploaded.

1. Save the PDF to your phone first if it is an email attachment, then open Fill and Sign PDF and choose the file.
2. Look at the first page. A plain form with no fillable fields, a packet of several pages and a scan all work. A packet lists the pages that need filling, so you can jump to them.
3. Tap a blank line and type. Tap a box to tick it. Tap it again to take the mark off.
4. Add your signature with your finger, and place it on the signature line.
5. Add the date next to it, or wherever the form asks for one.
6. Choose the whole document or only the pages you filled, then press Share or email. Your phone's share sheet opens with the PDF attached.

What if the form has no fillable fields?

You can still fill it. Some forms are only a picture of a form, so tapping a line does nothing in most apps. Here the tool finds the blank lines and boxes on each page and lets you type on them. You can also place text, check marks and a signature anywhere on the page. For a longer walk through, see how to fill out a PDF that is not fillable.

Which kind of form do I have?

• Fillable form: tapping a field lets you type. Fill it in as normal.
• Flat form: tapping does nothing. The tool finds the lines, or you place text yourself.
• Packet: many pages, only a few need you. Use the page list to jump, and send back only those pages if that is what was asked.
• Scan or photo of a form: it works like a flat form, and the text you add sits on top of the picture.

How do I make a clean signature with my finger?

Go slowly and use the whole width of the signature box. Turn your phone sideways if the box feels cramped. If it comes out wobbly, clear it and try again, or type your name and pick a style instead. You can also sign a plain sheet of paper, take a photo and upload that.

Your signature is a picture of your signature placed on the page. It is not a certificate-based digital signature, which carries a record of who signed and when. Some forms need a particular method, so ask who sent it. For the law behind this, see is a signature on an iPad legally binding. This is general information, not legal advice.

How do I stop the keyboard and small boxes getting in the way?

Pinch to zoom in on the line you are filling, type, then zoom out. The keyboard covers the lower half of the screen, so scroll the line up before you tap it. Zoom in again on each page you changed, and check that the text sits on the line and not across a printed word.

A worked example

Maya is starting a new job. HR emails a benefits form as a plain PDF with six pages, and only the last two need her. She saves it to her phone and opens it in Fill and Sign PDF. The packet list shows pages five and six. She types her details, ticks her choices, signs with her finger, adds the date and sends back only those two pages.

What about tax and immigration forms?

PDFinish only helps you type on a form and sign it. We never tell you what to put in a tax or immigration form, which one applies to you or when it is due. Follow the instructions from whoever issued the form, and check with a professional if you are unsure. This is general information, not legal or tax advice.

Common problems and fixes

• The attachment will not open in the tool. Save it to your phone first, then choose it from there.
• Your signature covers a printed word. Resize it and drag it back onto the line.
• You signed too early. Start again from your original file, fill first, sign last.
• The file is too big to email. Run it through Compress PDF and send that.
• You only need to sign. Sign PDF is the shorter route, and how to fill and sign a PDF covers the same job on any device.

Where does your form go?

Filling, signing and saving run in your browser. Share or email hands the file from your phone to the app you pick, such as Mail or Messages, and it never passes through our servers. The saved copy is named with the date, such as lease-signed-2026-10-26.pdf. Keep it, and keep the sent message so you can show when you sent it.

2 free uses in total, no account needed. Free files can be up to 50 MB.

Sources

• PDFinish's own Fill and Sign PDF page, for the form types, packets, signing, sharing, file naming and limits, as of November 2026.