Download Letro

Letro, on every device you trust

Secure, evidential client communication on your phone, tablet and in the browser. One encrypted workspace, wherever you work.

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Choose your platform

Install once. Sign in everywhere

Conversations, files and your PostNumber identity follow you to every device you verify.

App Store

iPhone & iPad

The native Letro app for iPhone and iPad, end-to-end encrypted on your device.

Download on the App Store
Coming soon
Google Play

Android

The native Letro app for Android phones and tablets, with the same end-to-end encryption.

Coming soon
This device
Any modern browser

Web app

The full Letro in your browser. Nothing to install.

Open the web app

Trouble installing? Contact support — or browse the Help Center.

Get started

From download to first message in 3 steps

Read the setup guide →
01

Download Letro

Install the app on your phone or tablet — or open the web app in any modern browser.

Choose your platform →
02

Get your PostNumber

Verify your identity once with your passport. Everyone you talk to knows exactly who is on the other side.

What is PostNumber? →
03

Join your workspace

Accept your organisation’s invite, or create a workspace and bring your clients and colleagues in.

Invite someone →
Invite someone

Encryption works best when both sides have it

Send a colleague or client a short introduction to Letro, with a link to download it on their device.

Opens your email app with the introduction and link ready to send.

Or share the link

Rolling Letro out to your firm? We set up your workspace, verify your team and onboard your first clients with you.