How to add an electronic signature in Adobe Acrobat Reader on iPhone
What you actually have is a PDF opened in Acrobat Reader on your iPhone. Here is how it gets signed and sent back, on the phone in your hand — no printer, no scanner, no account.
Option A · free · nothing to install
Acrobat Reader’s own Fill & Sign — free, and already open
If the PDF is already in Acrobat Reader, its Fill & Sign tool will sign it without installing anything else. That is genuinely the shortest path here, and we would rather say so than pretend otherwise.
- Open what you have in Adobe Acrobat Reader. What you are dealing with is a PDF opened in Acrobat Reader on your iPhone.
- Get it to a screen that can sign. You mostly do not need to get it out — Acrobat Reader has a Fill & Sign tool of its own. If you would rather not sign in Adobe, use the share icon to send the PDF elsewhere.
- Sign it. Tap the + at the bottom right of Markup, choose Signature, sign with your fingertip, tap Done, then drag the signature onto the line and pull the blue handles until it sits on the line rather than through the text underneath.
- Send it back. Share the signed PDF from whichever app you used.
If this is a one-off, stop here. The free route above signs the document and sends it back. Where it gets slow is repetition: Apple Markup holds one signature and no initials, text boxes do not snap to the form’s lines, there is no date shortcut, and nothing you place is flattened into the page.
Option B · with Signed
Sign it with Signed instead
Same document, fewer taps — because the signature, the initials and the date are already saved, and everything you place is flattened into the exported PDF.
- Share the PDF into Signed. From the same share sheet you reached out of Adobe Acrobat Reader, pick Signed — or import the PDF from inside the app. It stays on your iPhone: nothing is uploaded and there is no cloud copy.
- Drop in the signature you already saved. Tap the signature line and place the signature you made once — drawn with a fingertip, typed in a real handwriting style, or generated with AI. You never redraw it per document.
- Fill in the rest of the page. Add the date, your initials, your name, text and checkmarks with the matching tools. Today’s date fills itself in and saved initials are one tap per page.
- Export a flattened PDF and send that. Export the signed copy flattened, so the signature and every field become part of the page rather than a layer someone can drag off it. Then share the signed PDF from whichever app you used.
The catch with Adobe Acrobat Reader
Acrobat Reader repeatedly offers a paid subscription for editing, exporting and converting. Fill & Sign is not the part you have to pay for, so read the prompt before you tap it.
Signed signs PDFs. It does not convert file formats, sync your files, or send documents out for someone else’s signature — which is why anything that is not already a PDF goes through Adobe Acrobat Reader’s own export first.
Other pdf & reading apps apps
Signing from a different app
See all 62 apps → · know the document but not the app? Pick it by document type → · comparing services instead? See the e-sign alternatives →
Signed is a signing tool, not legal advice. Whether an electronically signed copy is accepted depends on the document, the counterparty and where you are — for anything high-stakes, check what your jurisdiction requires, including whether a notary or witnesses are needed. Adobe Acrobat Reader is a trademark of its respective owner and this page is not endorsed by or affiliated with it; Apple, Markup, iPhone and iOS are trademarks of Apple Inc. App interfaces change, so a menu may have moved since this was written.