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Guides · October 20, 2026 · 6 min read

Signing on a phone: designing for the signer

Many signers open your document on a phone. A few choices you make as the sender decide whether they finish in three minutes or give up. Here is how to design documents that work on a small screen.

By the eSora Sign team

Your signer is probably on a phone

When you send a document, you are usually at a desk with a large screen. Your signer often is not. They open the email on a phone, between meetings, on a bus, or standing in a kitchen. If the document is hard to read or the fields are hard to tap, they put it off. Many never come back.

eSora Sign is designed so that a typical signing takes about 3 minutes on a phone. The signer does not need an account or an app. But the document you send still shapes the experience. This guide covers the choices that make the biggest difference.

What the signer sees

On a phone, eSora Sign guides the signer from one field to the next. A bar at the bottom shows how many fields are left and moves them to the next one. They can zoom into the page, type or draw their signature, and save and finish later if they need to find information. If something is unclear, they can ask you a question without leaving the page. If they are not the right person, they can pass the document to someone else. If they disagree, they can decline and tell you why.

Signers can switch the page to English or French and turn on accessibility options: larger text, high contrast, and a screen-reader view that presents fields in a simple, linear form.

Fewer fields, better fields

Every field is one more tap. Before you send, ask whether each field is needed. If you already know the signer's name, email or company, prefill those fields and set them to read-only. The signer sees the value but does not have to type it.

Use the right field type. A date field opens a date picker. A dropdown avoids typing. A checkbox is faster than typing yes. A number field brings up the number keyboard on a phone. Each of these saves the signer time and reduces errors.

Use validation for things that have a format. eSora Sign can check that a text field looks like an email, a phone number, a number or a Canadian postal code. The signer sees a clear message straight away instead of you finding the mistake later.

Show only what applies

Long forms often contain sections that only apply to some people. Instead of asking everyone to skip them, use Show only if. For example, show Hours per week only when Employment type is Part-time, or show Spouse's name only when Marital status is Married. Signers only see what applies to them, and the form feels shorter because it is.

Make the document readable

A PDF designed for letter-size paper can be hard to read on a 6-inch screen. A few habits help.

Use a clear font at a normal size. Eleven or twelve point text is readable when zoomed. Eight point legal text is not.

Avoid tiny tables with many columns. If you need a table, keep it to a few columns, or break it into rows.

Put fields where they belong. Place each field next to the text it relates to, with enough room around it to tap. Fields squeezed into narrow table cells are hard to hit with a finger.

Put signature fields at natural points, usually at the end of a section, not in the middle of a paragraph.

If you send Word, PowerPoint or Excel files, check the converted PDF before you send. eSora Sign converts everything to PDF, and the preview shows exactly what signers will see.

Attachments from the camera

If you need a document from the signer, such as a void cheque, a certificate or a photo of an ID card for your records, use an Attachment field. On a phone, the signer can take a photo directly. That is far easier than asking them to scan something and email it separately. Only ask for attachments you actually need, and keep sensitive images to a minimum.

Keep identity checks light

An email code is the easiest check on a phone because the code arrives in the same app the signer is already using. SMS codes are almost as easy, and many phones fill them in automatically. Access codes require the signer to remember or find a code you gave them, so tell them about it in advance. Photo ID with a selfie works well on a phone camera, but adds a minute or two, so save it for documents that need it.

Write for a small screen

Your email message matters more on a phone, because the signer reads it before they decide whether to sign now or later. Put the important part first: what the document is and when you need it. Keep it to two or three sentences. A clear message like 'Your offer letter for Store Associate. Please sign by Thursday.' works better than three paragraphs of context.

In person, on your device

Sometimes the signer is right in front of you. A contractor on site, a patient at reception, a customer at a counter. Use the In person role and hand them your phone or tablet. They sign on your device, and the record shows it was signed in person, with the device and time. Everything else, including the certificate, works the same way.

Test it yourself

The most useful thing you can do is send the document to yourself and sign it on your own phone before you send it to anyone else. Notice where you have to zoom, which fields are hard to tap, and anything you had to read twice. Fix those things, and every signer after you will have an easier time.

This article is general information, not legal advice.