How to add a signature to a PDF on iPhone (3 ways)

Someone emailed you a PDF and needs it signed. You’re on your iPhone. Here are the three real ways to do it, from “built-in and free” to “fastest and cleanest” — including the parts Apple’s built-in tools don’t handle well.

Option 1 — iOS Markup (built in, free)

iOS can sign PDFs without any extra app:

Open the PDF (from Mail, Files, or Messages) and tap the Markup icon (the pen tip).
Tap + → Signature.
Draw your signature with your finger, then drag it onto the signature line and resize.
Tap Done and reply with the signed file.

Good: free, already on your phone. The catches: Markup gives you exactly one saved signature style, there’s no automatic date/initials/text fields, multi-page contracts get fiddly, and the signature sits as an annotation rather than being flattened into the document — some recipients’ software lets them move or delete it.

Option 2 — the Files app

The Files app uses the same Markup engine: long-press a PDF → Quick Look → Markup icon → signature. Same strengths, same limitations as Option 1. It’s most useful when the PDF is already saved in iCloud Drive.

Option 3 — a dedicated signature app (best for anything beyond one quick scribble)

A purpose-built signature app for iPhone like Signed exists for the gaps Markup leaves:

A real signature library. Draw once, or generate a handwritten-style signature with AI, and reuse it on every document — consistent and clean.
All the fields, not just the signature. Date (auto-filled with today), name, initials, text, checkmarks — placed exactly where they belong.
A flattened, final PDF. Signed exports the document with your signature baked into the page, so it can’t be nudged or stripped by someone else’s PDF reader.
Privacy. Signed is local-first — the document never leaves your iPhone. With cloud e-sign services, your lease or NDA goes to someone’s server first.

The flow: import the PDF from Mail/Files/Photos → tap where the signature goes → place it (plus the date, which fills itself) → tap Finish → share the signed copy back.

Which one should you use?

Situation	Use
One-off, single signature, casual document	Markup (Option 1)
PDF already in iCloud Drive	Files (Option 2)
You sign things regularly, need dates/initials, or care that the output is final and private	A signature app (Option 3)

Before you sign: get a signature you like

If you’ve never been happy with your finger-drawn signature, spend one minute in our free signature generator — draw it big (steadier), or type your name and pick from 15 handwriting styles. Save the version you like and use it everywhere.