Proton’s AI assistant with encrypted saved conversations
SwitzerlandEFTAFree plan Ownership reviewed, controller unresolvedHigh non-EU dependencyScope verdict
Proton AG is CHE-354.686.492. Proton calls Fondation Proton its primary shareholder and says a change of control needs Foundation consent. Official Foundation statutes show that the board appoints its successors and decides by majority. Proton AG’s April 2026 articles distinguish ordinary, voting-privileged and non-voting instruments, but do not identify their current holders. The Foundation’s exact voting stake and the full control arrangement remain unresolved.
Operational dependency warning
Current public evidence shows 5 non-European infrastructure or email dependencies across 5 providers: Atlassian Pty Ltd, Chargebee Inc, PayPal group, Stripe Inc, Zendesk Inc. The reviewed operational path is therefore not entirely European.
Lumo is a hosted AI assistant operated by Proton AG in Switzerland. It supports writing, questions, files, images and projects, with guest access and Free, Plus and business plans. Proton says inference runs on infrastructure it controls in Europe.
Saved conversations use zero-access encryption, but the inference server must decrypt prompts to generate answers. Closing a normal saved conversation is not the same as deleting it; Ghost mode is a separate option. The mobile clients have GPLv3 licences, which does not establish a self-hostable version of the complete service.
Checked 18 September 2026 in EUR: Free has limits; Plus is €12.99 monthly or €119.88 billed annually (€9.99/month equivalent). Professional is €14.99/user monthly or €143.88/user annually; business taxes may apply. Consumer tax treatment was not itemized on the price page. Subscriptions renew automatically and paid use is subject to fair use. The terms limit initial refunds to unused days within 30 days, with payment-method exceptions.
Data and operations
Verified operational dependencies, shown separately from ownership and from the service's core data hosting.
Core service hosting
Public website
Incoming business email
Authorised outbound email
Search result source
Supporting services
Why this matters
The published disclosure lists Zendesk Inc for supporting services. Depending on the function, account or customer data may reach this non-European provider. See the source for the documented scope.
Supporting services
Why this matters
The published disclosure lists Atlassian Pty Ltd for supporting services. Depending on the function, account or customer data may reach this non-European provider. See the source for the documented scope.
Payment processing
Why this matters
When this payment method is used, Stripe Inc processes payment and billing data. This role alone does not establish access to the service's other customer content.
Payment processing
Why this matters
When this payment method is used, PayPal group processes payment and billing data. This role alone does not establish access to the service's other customer content.
Payment processing
Why this matters
When this payment method is used, Chargebee Inc processes payment and billing data. This role alone does not establish access to the service's other customer content.
Supporting services
Supporting services
Germany
