Client communication built for the obligations you actually carry
Reports, tax statements, client instructions and everyday questions — in one Swiss-hosted, end-to-end encrypted channel your clients open from their phone.
Not another chat app · Not another portal
Three things your clients do with you — in one channel.
The everyday work that runs on email and WhatsApp today — Swiss-hosted, end-to-end encrypted, on one record.
Deliver documents through a Workspace
Each client has one secure space for everything you share. Nothing goes as an attachment, nothing sits in a personal inbox. You see what was delivered, when, to whom.
Answer questions without leaving the record
The quick question that used to go to WhatsApp stays in the same auditable channel as the documents. Your team answers from one place.
Onboard clients with PostNumber
A verified, permanent identity is issued at account creation. Every client in your channel is a verified person, tied to a verified address.
Private AI, inside your organisation’s environment
Documents and drafts are processed in an isolated, Letro-operated European environment assigned to your firm. No client data to a third-party model, nothing used for training.
Built for the regulatory context, not adapted to it.
Infrastructure in Switzerland, operated by a Swiss company — shaped to your risk profile.
End-to-end on the Matrix open protocol; keys stay on your devices.
Exportable, timestamped, tamper-evident.
Cryptography independently audited (vodozemac, Least Authority 2022). Independent penetration test of Letro by ImmuniWeb underway — September 2026.
Request a security briefing
See where your firm stands.
A 90-second calculator shows your exposure range across five layers, the size of your potential insurance gap, and the procedures that reduce both. No form, no gate. The five-step migration off WhatsApp is documented in the whitepaper.
