The best signature app for iPhone: which one fits your paperwork

A lease, a freelance contract or a school permission slip arrives with "please sign and return" and no printer in sight. The best signature app for iPhone depends on whether you sign that file yourself or send a document out for other people to sign. Five iPhone options split on how you sign, whether you need an account and where the file goes.

Why the right signature app for iPhone matters

The right signature app for iPhone saves you a print, sign and scan cycle, and it keeps the pages sharp and the file small enough for email. A wrong pick costs time in the other direction: a sign-up screen before your first signature, a trial clock, or an upload of a private lease to a service you did not plan to use.

Most paperwork that reaches you is ordinary: a rental application, an invoice to approve, a consent form from a clinic. The sender wants your signature, your printed name and a date on the right line.

The two jobs: sign it yourself vs. send it for signature

Signature apps do one of two jobs. The first job is a visual signature: you receive a PDF, draw your handwritten signature on it, and send it back. The second job is a signature request: you send a document to other people, the service guides each signer through the fields, and it keeps a record of who signed and when.

The second job often comes with certificate-based or audit-trail features that prove identity and detect changes. The difference between an electronic and a digital signature explains what each one means legally. Markup and MRS do the first job; Docusign and Signeasy are built for the second.

How to pick and use a signature app, step by step

A signature app choice takes about fifteen minutes with one real form from your inbox. Run the same form through two apps and compare.

1. Decide the job. Look at the email. A plain PDF attachment means you sign it yourself; a review-and-sign button means the sender already uses a request service, and you sign inside their link.
2. Check the account and the upload. Note whether the app asks you to sign up before the first signature and whether the document leaves your phone. A lease or a medical form carries data you may want to keep on the device.
3. Draw once and save. Draw your signature with your finger, and save it so the next form takes a tap. Make a second one with your initials if your forms ask for them.
4. Place and resize. Drag the signature onto the line, then resize it to about the height of two lines of printed text. Zoom in to line it up, then zoom out to see the page the way the recipient will.
5. Share it back. Send the signed PDF through the iOS share sheet by Mail, Messages or AirDrop, or save it to Files. Send the PDF file, never a screenshot of one page.
6. Keep a copy. Save the signed version where you will find it next year, in a folder named after the landlord, client or school.

MRS covers steps 2 to 6 on the phone: the Sign document tool scans or imports the form and opens the editor ready to sign, with no account and no upload. The full walkthrough with Markup and MRS is in the guide on how to sign a PDF on iPhone.

The part people get wrong: picking a request service for a one-signature job

Many people install a request service to sign one PDF and then meet a sign-up screen, a trial or a monthly document limit. A request service earns its place when you send contracts to several signers and need a record of who signed. For your own signature on a file you received, a visual signature from Markup or a PDF app is the shorter path.

The 5 signature apps compared

Markup, Acrobat Reader, Docusign, Signeasy and MRS all put a signature on a document, and they split on the job they serve. Rival facts come from each vendor's own page or App Store listing at the time of writing; plans and prices are on each vendor's site.

Markup is the signing tool built into iOS. Apple's iPhone User Guide says you tap Add Signature, sign with your finger and drag the signature into place, and that the iPhone saves it for next time. You can keep several, such as a nickname or initials, and AutoFill can fill related form fields from your contact card.

Acrobat Reader includes Fill & Sign. The Acrobat Reader App Store listing says Adobe Fill & Sign is free and available in the app, lets you fill, sign and send forms, and links storage such as Microsoft OneDrive, Dropbox and Google Drive. Adobe's iOS Fill & Sign guide says you draw a signature, use an image or capture one, and that signatures and initials are permanent once saved because the PDF flattens.

Docusign is built for sending. The Docusign App Store listing says you can send and monitor agreements from your device, that signing is free for all parties, and that a complete audit trail tracks who signed when and where. The Docusign eSignature page says signers can complete documents on any device with no account required.

Signeasy covers both sides on Apple devices. Its App Store listing says you can draw, scan or import your signature, add fields for clients to fill and sign, and collect signatures in person on an iPhone or iPad. The listing names a digital audit trail with the signer's email, device IP and completion time, offline editing and signing, and a 7-day trial before a paid plan.

MRS is an iPhone scanner and PDF editor that does the first job in full. You draw with a finger in black or blue ink, MRS saves your 5 newest signatures, and you place, move, resize and rotate a signature on any page. The Sign document tool scans paper with Apple's document camera or imports a PDF, then opens the editor ready to sign.

The same editor adds typed text in 7 fonts, sizes 12 to 48 and 9 colors for dates and printed names, plus drawings, an image or logo, an eraser and extra pages. Documents stay on the iPhone in folders with a 30-day Trash, and you share them through the iOS share sheet. MRS runs on iPhone with iOS 16 or later, in 33 languages; its signature is a visual handwritten one, and it does not send documents to other signers.

Which one to pick

Your pick follows the job from step 1. Choose Markup for a single PDF from Mail, MRS when the form starts on paper or you sign often and want the signed copies in one private library, and Acrobat Reader if your files already live in Adobe tools. Choose Docusign or Signeasy when you are the sender and need every signer tracked.

Tips for a signature that looks right on paper

A signature looks right when it reads like ink on the printed page.

• Turn the phone sideways: a wider pad gives a longer, steadier stroke, a tip Apple's guide gives for Markup too.
• Pick blue ink for originals: blue stands out from black print, so the recipient sees at a glance which mark is yours.
• Match the line: a signature about two text lines tall fits most forms; a full-width scrawl covers the printed label.
• Add the date and name in text: type "October 15, 2026" and your printed name next to the line in a plain font at size 12 to 14.
• Scan paper flat: a form shot on a dark table by a window comes out straight and sharp, as the guide on how to scan documents on iPhone shows.

Draw the signature fresh

A signature drawn on the screen in your own hand looks like you. A photo of a signature from an old letter carries a grey background and a blurry edge, so draw a new one with your finger and save it in the app.

How to check a signed PDF before you send it

A signed PDF is ready when the recipient can act on it without a second email. Open the file one more time and check these points.

• Every line: does each signature line, initials box and date field have a mark?
• Right version: do the names, amounts and dates on page one match the newest copy?
• Readable pages: are all pages straight, in order and sharp at full zoom?
• File type: is the attachment a PDF, not a set of screenshots?
• Your copy: is the signed file saved where you can find it?

A two-minute test

A two-minute test catches most problems. Send the signed PDF to yourself first, open it in Mail on the iPhone, and scroll every page the way the recipient will.

Common mistakes when choosing a signature app

The common mistakes when choosing a signature app come from mixing up the two jobs.

• Sending a plain PDF through a request service you do not need: it adds a sign-up and a limit for a one-signature job. Sign it yourself instead.
• Drawing your signature on a form that asks for a request: if the sender's email has a signing link, sign inside the link, or the sender's record stays incomplete.
• Ignoring where the file goes: a lease or a medical form carries personal data, so read whether the app uploads documents before you sign a year of paperwork in it.
• Forgetting the printed name and date: many forms ask for signature, name and date on one line.
• Signing the wrong copy: an old email thread can carry last year's version.

Edge case: a form that asks for a certified digital signature

Some forms from banks, government offices or regulated industries ask for a certified or qualified digital signature. That is a cryptographic signature tied to a certificate that proves who signed and shows whether the file changed, as the Wikipedia article on electronic signatures explains. A drawn signature from Markup or MRS is a visual electronic signature, so ask the sender which process they accept, or use the service they name.

In the United States, the ESIGN Act says a signature may not be denied legal effect solely because it is in electronic form, with exceptions such as wills and court filings. This is general information, not legal advice.

Your signature app checklist and next steps

Your signature app checklist fits on one screen.

• Job named: sign it yourself, or send it to other signers.
• Account fit: an account only where you send documents to others.
• Signature saved: drawn once, with initials if your forms ask for them.
• Text tools ready: date and printed name typed next to each signature.
• Files placed: you know where every signed document lives and who can see it.
• Copy kept: the signed PDF in a folder you can find next year.

If your answers point to signing paper forms and PDFs yourself, download MRS, scan this week's form and sign it tonight. The guide to PDF editing basics on mobile covers text boxes and alignment, the best free PDF editor for iPhone compares editors for other edits, and MRS support answers app questions.