Digital signature on the iPhone This can mean two different things: inserting a handwritten signature into a PDF using Apple's native tools, or creating an electronic signature with authentication evidence and, when necessary, a digital certificate. In iOS 26, the Preview app began to centralize features for filling out and signing PDFs directly on the device.
This distinction is important because drawing a name with your finger on an iPhone does not automatically transform the file into a cryptographic digital signature. For contracts and other documents, the appropriate level depends on the risk, the evidence required, and the applicable legal formalities.
In this guide, we show you how to sign a PDF on your iPhone using Preview, how to scan and sign documents in the Notes app, and how to use a specialized platform when you need a more structured workflow.
Summary
- In iOS 26, PDFs can be filled out and signed in the Preview app.
- The Notes app lets you scan paper documents and add a signature via Markup.
- A signature drawn on the screen is different from a digital signature based on cryptography and a certificate.
- Law No. 14.063/2020 distinguishes between simple, advanced, and qualified electronic signatures.
- ZapSign can be used via the iPhone's browser to create, send, authenticate, and track documents.
- For qualified signatures, the workflow must use a compatible ICP-Brasil digital certificate.
Quick facts
- PDF on iPhone: a Apple It informs that the Preview app allows you to fill out PDF forms and add signatures directly on your iPhone.
- Paper document: o Apple Support It teaches you how to scan documents using the Notes app and sign them using Markup.
- Three legal modalities: a Law No. 14.063 / 2020 It classifies electronic signatures into simple, advanced, and qualified categories.
What is digital signature?
In technical terms, a digital signature is a type of... electronic signature Based on asymmetric cryptography, it links the signatory to a certificate and allows verification of whether the document has undergone changes incompatible with the signature.
This is different from simply drawing a signature with your finger on a screen. The handwritten mark may be part of a valid electronic stream, but, in isolation, it does not possess the same cryptographic properties as a digital signature.
In Brazil, legal validity It must be analyzed according to the method used, the evidence produced, and the formalities of the act. Provisional Measure No. 2.200-2/2001 It established ICP-Brasil, and Provisional Measure No. 983/2020, cited in the original version of this article, was converted into Law No. 14.063/2020, which is now the reference for the classification of electronic signatures.
When the signature uses a digital certificate da ICP-BrazilIt is classified as a qualified electronic signature. Certificates can be associated with a natural or legal person; the e-CNPJFor example, it's a common term for certificates linked to companies.
When we founded ZapSign, we had two very clear principles: electronic signatures needed to be legally valid and simple to use. On mobile phones, this becomes even more evident: security needs to add trust to the process without turning a quick signature into an unnecessary sequence of hurdles.
| How to sign on iPhone | What happens | Type of evidence | When it makes sense |
|---|---|---|---|
| Preview / Markup | You insert a handwritten representation into the PDF. | Visual branding in the file | Forms and documents where this method is accepted. |
| Notes + Marking | You scan the document and add a visual signature. | Digitization + visual branding | When the document still exists only on paper. |
| Electronic signature platform | The document circulates in a flow with signatories and authentications. | Registrations, authentications and reporting | Contracts and processes that require traceability. |
| ICP-Brazil Certificate | A qualified cryptographic signature is generated. | Certificate, cryptographic key and validation | When the law, the system, or the risk requires a qualified signature. |
💡 Tip! Need a free digital signature? Click here and create yours now!
What is the importance of digital signature?
The main advantage of the electronic process is reducing the effort required to prepare, send, sign, and track documents between people who are not in the same location. On the iPhone, this adds mobility: the signatory can review and complete steps using their own device.
Faster document signing
In physical processes, contracts may depend on printing, movement, transportation, or scanning. In an electronic workflow, these steps can be reduced, although the total time still depends on reading, approval, and the availability of the participants.
Reduced costs
When paper is no longer needed, expenses related to printing, courier services, postage, transportation, and archiving can also decrease. The actual savings vary depending on the volume and process adopted by the company.
Fewer commutes
Signing via mobile phone allows people in different cities or countries to participate in the same workflow without physically transporting the document. This can simplify approvals, hiring, and administrative routines.
Reduction in paper consumption and sustainability
Electronic documents can reduce paper consumption and physical storage space when the process truly eliminates the need for printed copies. Sustainability, however, depends on the entire operation and not just the replacement of paper with digital files.
Faster deal closing
Remote signing reduces the time between sending and completing a document, but it doesn't, by itself, guarantee more closed deals. It primarily helps to remove operational friction after the parties are already ready to formalize the agreement.
Student Exchange
The iPhone allows you to open PDFs, insert a visual signature, scan documents, and access online signing platforms. For qualified operations, cloud certificates can also enable mobile use when the service and certificate are compatible.
⚠️ Also check out these related articles 👇
➡️ Learn how to sign with a digital certificate
➡️ Understand what a digital signature verifier is for
➡️ What is a digital contract and how to adopt one for your company
How do I sign a PDF on my iPhone using the Preview app?
In iOS 26, the most straightforward way to fill out and sign PDFs is to use the app. PreviewAccording to Apple's current documentation, you can open a PDF, use the fill feature, and add a signature or text box.
- Open the Preview app on your iPhone.
- Select the PDF you wish to fill out or sign.
- Tap the form completion button when available.
- Tap Add and choose the subscription option.
- Create or select the saved signature, adjust its size and position, and complete the document.
- Use Share to send or save the completed version.
The eight images below are from the original tutorial, produced before the Preview app existed on the iPhone. They show the old workflow through the Files app and the Markup tool and have been preserved for reference. In earlier versions or compatible apps, Markup still allows you to add a signature.
Step 1
In the original workflow, the first step was to open the document using the Files app.
Step 2
Next, you needed to open the Markup tools using the corresponding icon.
Step 3
The add button allowed you to select the "Subscription" option. This concept remains in the current system, although the interface is different.
Step 4
If there is no saved signature, you can create one by drawing with your finger on the screen.
Step 5
Then, the signature can be resized and positioned in the desired area of the PDF.
Step 6
Finish editing and save the file. Remember that this operation inserts a visual representation of the signature; it does not, by itself, create a digital certificate.
Step 7
After saving, use the sharing menu to choose the sending channel.
Step 8
Choose the application or destination where you want to share or store the signed version.
How do I scan and sign a document in the Notes app?
If the document only exists on paper, the Notes app remains a native option for digitizing it. In iOS 26, Apple instructs users to open or create a note, tap on... Attachment > Scan Documents and use the camera to capture the pages.
After scanning, open the document, tap Markup, choose Add, and select Signature. You can use a saved signature or create one with your finger.
The following images show the 2022 interface. The procedure remains conceptually similar, but icons and command names have changed.
Step 1
Open or create a note and start scanning documents from the attachments menu. In the old interface, this function appeared directly via the camera icon.
Step 2
Place the document on a stable surface and frame the page. Automatic mode can capture the page automatically; in manual mode, use the shutter button or a volume knob.
Step 3
Adjust the corners, rotation, or filters as needed, and repeat the capture for the remaining pages.
Step 4
Complete the scanning and save the document within the note.
Open the scanned document to access the editing and sharing tools.
Step 5
Open the Markup app, tap Add, and choose the subscription option.
Select an existing signature or create a new one with your finger.
Step 6
Resize and position the signature in the appropriate location on the document.
Step 7
Complete the editing and share the final version through the appropriate channel.
How do I sign documents on my iPhone using ZapSign?
When a document is part of a contract, business approval, or other workflow that requires greater traceability, an electronic signature platform offers features that are not available in a simple annotation on the PDF.
Using the iPhone's browser, the responsible party can create or upload the document to ZapSign, add signatories, choose authentication methods, position fields when necessary, and share the links. The signatory does not need to install a specific application to open the link and complete the process.
- Access your ZapSign account through your browser.
- Create a document and send the file to be signed.
- Add the signatories and configure the authentication methods appropriate to the risk.
- Define fields, order, and deadline, when necessary.
- Send the link and track the signatures through the dashboard.
If the workflow requires a qualified signature, ZapSign also allows you to configure a digital certificate signature. For truly mobile use, a cloud-based A3 certificate can be accessed via mobile phone on compatible services, without relying on a USB token connected to an iPhone.
More recently, I followed an application at ZapSign that is even more closely linked to mobile phones: Open Gateway uses information from the mobile network infrastructure itself to reinforce signer validation and combat identity fraud without creating a new step of friction. It's a good example of how the device can contribute to security without making the journey more difficult.
When should I use Markup, Platform, or Digital Certificate on iPhone?
For a simple form where the other party accepts a handwritten signature inserted into the PDF, Preview or Markup may be sufficient. For contracts, approvals, and documents where you need to better identify the signatory and preserve a history of the process, a specialized platform tends to offer additional evidence.
However, when the law, the system used, or internal policy requires a qualified electronic signature, the workflow must use an ICP-Brasil certificate. After signing, the document can be verified in a... digital signature verifier compatible.
Em digital contractsThe best method is one that combines appropriate formality, evidence proportionate to the risk, and an experience that the parties can actually complete via mobile phone.
Now that you know how to differentiate a visual signature on an iPhone from a structured electronic signature and a qualified digital signature, you can choose the method that is compatible with the document and the level of evidence required.
To use a platform that allows you to create, send, and track documents via mobile phone, Just click here to learn more about ZapSign..
Frequently Asked Questions (FAQ)
In iOS 26, you can open a PDF in the Preview app and add a signature. This handwritten mark is not automatically a cryptographic digital signature. For a workflow with authentication or a certificate, use a compatible platform.
Use the Preview app. Open the PDF, access the fill or markup, tap Add, and choose Signature. Then, create or select your signature, adjust its size and position, and save or share the file.
It may have value as an electronic signature depending on the context and evidence of the process. However, designing the signature does not automatically equate to a qualified ICP-Brasil signature. Some actions may require specific methods or formalities.
Yes, especially with cloud-based certificates and compatible services. Cloud-based A3 certificates can be accessed via mobile phone without a USB token. Availability for signing depends on the certificate, the platform, and the system in which it will be used.
In the Notes app, create or open a note, tap Attachment, and choose Scan Documents. After capturing, open the document, use Markup, tap Add > Signature, position the mark, and save the final version.
Getúlio Santos is the CEO of ZapSign, a lawyer, technology enthusiast, and entrepreneur.
