How to Sign a PDF on Your Phone (iPhone & Android)

Your phone is the easiest device to sign on — you can draw your signature with your finger, which feels just like signing on paper. The best part: you don't need to install any app. Here's how to sign a PDF on an iPhone or Android phone, whether someone sent it to you or you need to sign your own document.

Someone sent you a document to sign

This is the simplest case, and it works identically on iPhone and Android because it all happens in your browser.

Step 1: Open the email

You'll get an email with a secure signing link. Tap it — the document opens right in Safari (iPhone) or Chrome (Android). No app store, no download.

Step 2: Read the document

Scroll through the PDF on your screen. The signature field is highlighted so you can't miss where to sign.

Step 3: Sign with your finger

Tap the signature field and draw your signature with your finger. Prefer not to draw? You can type your name instead and it renders in a signature-style font. Redo it as many times as you like.

Step 4: Submit

Tap to confirm. Done. You and the sender both receive the completed PDF by email, with a full audit trail and a tamper-evident hash included.

You need to sign your own PDF

If the document is yours and you want a signed copy — or you need someone else to sign it — you can do everything from your phone's browser:

• Create a free SignovaX account (takes about 30 seconds).
• Upload your PDF from your phone.
• Place a signature field where it needs to go.
• Sign it yourself, or add someone's email to send it to them.

What about the built-in tools (iOS Markup)?

iPhones do have a built-in Markupfeature (in Files, Mail, or Photos) that lets you add a drawn signature to a PDF, and some Android PDF apps offer similar drawing tools. These are fine for quickly adding a mark to a document you're keeping for yourself.

The difference: those tools just draw on the file. They don't record who signed, when, or from where — so there's no audit trail and no tamper-evidence. For anything that matters — contracts, agreements, anything you might need to prove later — use a proper e-signature flow that captures that evidence.

Is a phone signature legally binding?

Yes. A signature made on your phone is just as valid as one made on a computer or on paper, under laws like the ESIGN Act and eIDAS — provided there's intent and a reliable record. More on that in are electronic signatures legally binding?

Common questions

Do I need an app to sign on my phone?

No. With SignovaX, signing happens entirely in your mobile browser. There's nothing to download or install.

Does the signer need an account?

No. If someone sends you a document, you just tap the link and sign. Only the person sending documents needs a (free) account.

Disclaimer: This article is for general informational purposes only and is not legal advice. Signature requirements vary by location and document type.