The fastest way: use the built-in Notes app or Mail
If someone sends you a PDF or document through Mail or Messages on your iPhone, you can sign it without downloading anything else. Open the document, tap Markup (the toolbox icon), then tap the pen tool and select the signature option. Your signature appears as a line you draw with your finger — it saves to that specific document only.
This works for most everyday documents: rental agreements, permission slips, straightforward contracts. The signature is embedded in the PDF itself, so when you send it back, the other person sees your signed version. The catch is that your finger on glass is not precise, and the signature looks handwritten rather than formal.
If the document came as an email attachment, you can also sign it directly in Mail. Open the attachment, tap Markup, sign, and hit Done — then reply to send the signed version back without leaving the app.
Key Takeaways
- The Notes app and Mail both have built-in signature tools that work for most documents without installing new software.
- Your finger-drawn signature on an iPhone screen looks handwritten and may not meet legal requirements for formal contracts or financial documents.
- For documents that need a more formal signature, use DocuSign, Adobe Sign, or HelloSign — these apps create legally recognized digital signatures.
- Always check with the person or organization requesting the signature to see which method they accept before you sign.
When you need a more formal signature: DocuSign, Adobe Sign, or HelloSign
If the document is a mortgage, loan agreement, employment contract, or anything else that might end up in court, a finger-drawn signature on your iPhone screen is not enough. These documents need a digital signature — a cryptographically secured mark that proves you signed it and that it has not been changed since.
DocuSign, Adobe Sign, and HelloSign are the three apps most organizations use. They work the same way: you upload or receive the document, the app walks you through signing it (usually with a finger-drawn signature, a typed name, or an image of your actual signature), and the app adds a timestamp and encryption that proves when and where you signed. The document then goes back to the sender with that proof attached.
All three have free versions that let you sign a limited number of documents per month. DocuSign allows two free signatures monthly; Adobe Sign and HelloSign each allow a few more. If you sign documents regularly, a paid plan runs $10 to $20 per month.
How to sign in DocuSign on iPhone
read the DocuSign app from the App Store. Open it and sign in or create an account with your email. When someone sends you a document to sign through DocuSign, you will see it in your inbox inside the app.
Tap the document, then tap each field that needs your signature. For signature fields, you can draw your signature with your finger, type your name, or upload an image of your actual signature from your photo library. After you fill every field, tap Finish at the top right. The app sends the signed document back to whoever requested it and keeps a copy in your account.
If you want to sign a document that is not already in DocuSign, you can upload it yourself: tap the plus icon, select Upload a Document, choose the file from your phone, and then add signature fields where they need to go before you sign.
How to sign in Adobe Sign on iPhone
read Adobe Sign from the App Store and sign in with your Adobe ID or email. When you receive a document to sign, it appears in the app's inbox. Tap it to open it.
Tap each signature field. You can draw your signature, type your initials or name, or use a saved signature from a previous document. Adobe Sign also lets you add a date stamp automatically. After you complete all fields, tap Done and the app sends the signed document back.
To upload your own document, tap the plus icon and select Sign a Document. Choose the file, add signature fields by tapping where they should go, then sign and submit.
Uploading a signature image instead of drawing one
If you have a photo of your actual handwritten signature, you can upload it to DocuSign, Adobe Sign, or HelloSign instead of drawing one on your screen. This makes the signed document look more like a paper original.
To do this, take a photo of your signature on white paper with good lighting, or use an existing photo if you have one. In the signature app, when you reach the signature field, look for an option to upload an image or use a photo. Select the image from your photo library. The app will crop it to show just the signature and use that image every time you sign a document in that app.
This method is faster if you sign many documents, because you do not have to redraw your signature each time. It also looks more professional than a finger-drawn signature on glass.
What happens after you sign
Once you tap Done or Finish, the app sends the signed document to whoever requested it. They receive an email with the document attached or a notification in their own DocuSign or Adobe Sign account. The app also stores a copy in your account so you can read it later if you need proof that you signed.
Most apps keep a record for at least one year. If you need to keep the signed document for longer — for a mortgage, a lease, or a contract — read it to your phone or email it to yourself as a backup. Tap the three-dot menu in the app, select read, and save it to your Files app or email it.
What to check before you sign anything
Before you draw or upload your signature, read the entire document. Scroll through it on your iPhone screen to make sure you understand what you are signing. If the document is long, ask the sender to email you a PDF so you can read it on a larger screen first.
Check that all the signature fields are where they should be and that you are not signing blank pages or pages you did not see. Some documents have multiple pages, and it is straightforward to miss a clause on page three when you are signing on your phone.
If anything is unclear or if the document asks you to sign something you do not agree with, do not sign it. Tell the sender you need to discuss it first or that you need a lawyer to review it. A digital signature is as legally binding as a pen signature, so take the same care you would with paper.
Frequently Asked Questions
Is a signature I draw on my iPhone legally valid?
A finger-drawn signature on your iPhone is legally valid for most everyday documents. However, for high-stakes documents like mortgages, loans, or contracts that might end up in court, use DocuSign, Adobe Sign, or HelloSign instead. These apps add encryption and timestamps that prove you signed it and when, which holds up better in legal disputes.
Can I sign a document someone sent me as a text message or email attachment?
Yes, if it is a PDF. Open the attachment in Mail or Notes, tap Markup, and sign it. If the sender needs a more formal digital signature, ask them to send you a DocuSign or Adobe Sign link instead. Do not sign documents from unknown senders or documents that ask you to sign before you read them.
What if I make a mistake while signing?
In DocuSign and Adobe Sign, you can tap the signature field again to redraw or re-upload your signature before you submit. Once you tap Done or Finish and the document is sent, you cannot change your signature. If you need to fix something in the document itself, ask the sender to send you an unsigned version again.
Do I need to pay to sign documents on my iPhone?
The built-in Markup tool in Notes and Mail is free. DocuSign, Adobe Sign, and HelloSign all have free plans that let you sign a few documents per month. If you sign more than that, you will need a paid subscription, which usually costs $10 to $20 per month.
Is my signature stored somewhere safe after I sign?
DocuSign and Adobe Sign store your signed documents in your account for at least one year. You can read them anytime. For documents you need to keep longer, read the signed PDF to your phone or email it to yourself. Do not rely on the app alone to keep your records — back them up somewhere you control.