How to get two people to sign the same PDF on iPhone

Two people need to sign the same document, and neither of you wants to find a printer. It sounds like it should be a one-tap thing on an iPhone, and it nearly is — but almost every guide about it is written by a company selling signature routing, so the answer you get is “sign up, add a signer, send”.

Sometimes that really is the right answer. Often it isn’t. Here’s the honest split.

First: are you together, or apart?

That one question decides everything.

Together — same room, one phone between you. Nothing to sign up for. One person signs, hands the phone over, the other signs, you export one file. This takes about ninety seconds and no service is involved. Skip to Method 1.

Apart, and you just need both signatures on one file. Email round-trip: you sign, send it, they sign the file you sent and send it back. Also free, also no account for the other person. That’s Method 2.

Apart, and you need to be able to prove who signed. This is where a routing service earns its money — DocuSign, Dropbox Sign, SignWell, PandaDoc and the rest exist mostly to produce an audit trail: a timestamped record of who opened the document, from which address, and when each person signed, plus reminders when someone sits on it and required fields so nobody misses page four. If a dispute over this document would be expensive, pay for that record. Nothing on this page replaces it.

Being blunt, because it’s the same limitation on every phone-based method here: Signed does not route documents between signers. It signs a PDF that’s on your phone — no sending, no tracking, no signer fields, no reminders. If the paragraph above describes your situation, use a routing tool. If it doesn’t, you’ve been about to pay a monthly subscription for a problem you don’t have.

The mistake that wastes an afternoon

Before the methods, the one failure worth naming: two people signing two separate copies.

You email the PDF to the other person. They open the original attachment, sign it, and send it back. Now you have two files — one with your signature, one with theirs — and no single document carrying both. It’s the most common way this goes wrong, and it’s invisible until someone asks for the executed copy.

The rule that prevents it: signatures go on one file, in sequence. Whoever signs second must open and sign the file the first person sent, not their own copy of the blank original.

Method 1: both of you in the same room

Nothing to install, if you don’t already have a signature app.

Open the PDF on the iPhone — from Mail, Files, or wherever it lives.
Tap the Markup (pen) icon.
Tap + → Signature, draw with a finger, place it on the first signature line, resize with the handles.
Hand the phone to the other person. They tap + → Signature again. iOS keeps a list of saved signatures — they tap Add or Remove Signature → + to draw their own, which is then saved as a second entry.
Drag their signature to the second line. Add dates as text boxes if the document asks for them.
Tap Done, then Share the signed file to both of you.

Where this is genuinely enough: a one-page agreement between two people who trust each other. Free, built in, done.

Where it gets tedious, honestly: finger-drawn signatures on glass take a few attempts each to look like anything; dates and initials are manual text boxes you nudge into position; and a multi-page document that wants both sets of initials on every page turns into real work — initialling every page is where most people give up on Markup.

If you’re the one who signs documents regularly, a signature app is worth it for your half: in Signed you build your signature once — draw it properly, type your name in a handwriting style, or generate one from your name — and after that it’s one tap with the date already filled in. The second person can still draw theirs with a finger; they don’t need the app, and they don’t need an account.

Method 2: one email round-trip

For two people who aren’t in the same place. Thirty seconds of care up front saves the two-half-signed-files mess.

1. Finish the document before anyone signs it

Fill in every blank — names, dates, amounts, terms — while it’s still editable, then export to PDF. A document that gets edited after a signature is on it is a problem you’ll be explaining later. Send a PDF, not a Word file.

2. Sign your half first, and flatten it

Sign, date, initial where required — then export a flattened copy. This matters more than it sounds: an unflattened signature is an annotation layer sitting on top of the page, which means it can be dragged out of place, deleted, or vanish when the other person prints the file. Flattening merges it into the page itself. Signed exports flattened by default; if you’re using Markup, the free equivalent is the print-to-PDF trick in how to flatten a signed PDF on iPhone.

The other person can still sign on top of a flattened file — flattening locks your marks down, it doesn’t lock the document.

3. Send it with instructions, not just an attachment

One short email prevents nearly every round of back-and-forth:

Attached is [document], with my signature already on it. Please sign and date on page [X] — on this attached copy, not a fresh one — and reply to this email with the signed PDF. I’ll send you the final version with both signatures for your records.

That “on this attached copy” clause is the whole point of the email.

4. Tell them how, if they ask

Most people will do it on the phone in their hand and don’t need to buy anything:

iPhone / iPad: open the attachment → Markup (pen) icon → + → Signature → draw → place → Done → reply with the signed copy. The full walkthrough is at how to sign a PDF from an email on iPhone.
Mac: open in Preview → Markup toolbar → Signature.
Windows: Adobe Acrobat Reader (free) → Fill & Sign.

Sending them a link is faster than explaining it in a reply.

5. Check what comes back, then distribute one final copy

Open the returned file and confirm both signatures are actually on it and nothing else changed. Then send that same file back to the other person so you’re both holding the identical executed copy — a two-party document isn’t finished when the second person signs, it’s finished when both of you have the same file. Name it so you can find it later: 2026-08-07 — [document] — EXECUTED.pdf.

Keep the email thread too. It’s a plain-English record of when you sent it and when they returned it. Not an audit trail, but not nothing.

Three or more signers, and other awkward cases

Three+ people: the round-trip still works, but it’s sequential — A signs and sends to B, B signs and sends to C — and every extra hop is another chance someone signs the wrong copy. Past two signers, a routing service stops being a luxury.
Signatures needed in a specific order (or simultaneously): email doesn’t enforce order. If the sequence matters formally, that’s a routing-tool requirement.
A witness or notary is required: some documents call for one, and no phone app of any kind satisfies that. Check the requirement before you sign, not after.
Landlord and tenant on a lease: the sender-side version of this, with the countersigning step written out, is at how to set up an online lease signing process.

What this approach doesn’t give you

Worth stating plainly, because the limits are exactly where a different tool is the right call:

No proof of who signed. An emailed PDF shows a signature arrived from an email address, not that a particular person made it.
No tracking or reminders. If they sit on it for a week, you find out by noticing.
No tamper-evident seal. Flattening and the email thread both help; neither is cryptographic proof the file wasn’t altered.
No legal opinion. Whether a document signed this way meets a requirement depends on the document type and where you are — this is a signing tool, not legal advice. Are electronic signatures accepted? is the honest version of that question, and for anything high-stakes, ask a lawyer rather than a guide.

The short version

Same room: one phone, Markup, hand it over, export once — free, no app required. Apart: you sign first, flatten, email it with “sign this copy, not a fresh one”, they sign and return it, you send the final file to both of you. Need proof of who signed and when, or more than two signers? Pay for a routing service — that record is the actual product.