Proton for Business for UK small businesses

Proton for Business is the commercial product range of Proton AG, the Swiss company founded in 2014 by a group of CERN scientists and launched through a crowdfunding campaign that raised more than half a million dollars from over ten thousand donors. The company is majority-owned by the non-profit Proton Foundation, takes no venture capital, and reports more than a hundred million accounts and over a hundred thousand business customers across its consumer and business base.

The business range covers six applications. Proton Mail provides encrypted email with zero-access encryption at rest and end-to-end encryption between Proton accounts, plus password-protected messages to external recipients. Proton Calendar and contacts are end-to-end encrypted. Proton Drive stores files encrypted client-side before upload, with Docs and Sheets providing real-time collaborative editing on those encrypted files. Proton Meet runs on Messaging Layer Security with host controls and recording. Proton VPN offers ad and malware blocking, split tunnelling and coverage across 140 countries. Proton Pass handles passwords, aliases and dark web monitoring. Lumo, the private AI assistant, completes the range on the Premium bundle.

Commercially the products are sold in two shapes. Product-specific plans — Mail Essentials, Drive Professional, VPN Essentials and Professional, Pass Essentials and Professional, Meet Professional and Lumo Professional — each cover one capability with per-plan minimum user counts. The Workspace bundles combine everything: Workspace Standard at $14.99 per user monthly with annual billing includes Mail, Calendar, Drive, Docs, Sheets, Meet, VPN and Pass with 1 TB of storage per user, fifteen custom domains and meetings of up to 100 participants; Workspace Premium at $24.99 adds Lumo, retention policies, 3 TB per user, twenty domains and 250 participants. Enterprise is negotiated directly.

What distinguishes Proton from the incumbents is the encryption model, and the distinctions matter. Mail is zero-access encrypted at rest, meaning Proton cannot read stored messages, but end-to-end encryption applies only between Proton accounts or through password-protected external messages — incoming mail from Gmail is briefly readable on Proton's servers, as Proton's own documentation states. Drive, Calendar, Pass and Meet are end-to-end encrypted. Desktop access to mail depends on the open-source Bridge application, because standard IMAP access is incompatible with the encryption model. Proton also states plainly that email metadata cannot be encrypted without breaking delivery.

UK Business Stack classifies Proton for Business as the communication and file layer of a privacy-focused stack: it replaces or complements Microsoft 365 and Google Workspace where encryption, open-source clients and European hosting carry more weight than integration breadth.

Proton for Business occupies the same shelf as Microsoft 365 and Google Workspace but argues from a different premise: that encryption by default, open-source clients and European data centres justify accepting narrower collaboration features. It can be adopted as a full suite replacement or mixed — Mail and Drive first, VPN and Pass alongside, Meet when needed.

The integration story is thinner than the incumbents by design. Desktop mail runs through Bridge rather than native IMAP; Calendar does not sync to Outlook or Google; SSO and SCIM exist only for VPN and Pass, not Mail; and there is no shared mailbox, only distribution lists. Migration is strongest for mail, contacts and calendars through Easy Switch, and weakest for files, where no Drive or Teams migration tool is documented.

The UK question is contractual and geographic. Proton AG in Geneva is the contracting party, hosting sits in Switzerland, Germany and Norway with no UK residency option, prices publish only in dollars, euros and Swiss francs, and the UK entity Proton Technologies Ltd exists in London alongside a Luxembourg EU representative. UK-approved standard contractual clauses are named in the data processing agreement.

The flow below reflects Proton's documented business setup guidance and support materials. UK Business Stack has not run a live Proton business migration for this review, so treat these steps as documented behaviour rather than tested behaviour.

Before committing to any business suite it is worth naming the honest alternatives. All of them provide mail and files; they differ in encryption depth, collaboration breadth, jurisdiction and price.

• Who you are contracting with. Proton AG in Geneva is the contracting party under the published terms; a UK entity, Proton Technologies Ltd, is registered at Companies House in London, and Proton Europe sàrl in Luxembourg acts as the EU representative.
• Currency and tax. No sterling price list exists — billing is in US dollars, euros or Swiss francs only — so budget holders absorb exchange-rate movement; business reverse-charge and VAT-identifier validation exist for business plans, but confirm the treatment at checkout.
• Where the data sits. Data centres are exclusively in Switzerland, Germany and Norway, with no UK residency option; the data processing agreement limits transfers to Switzerland, the EEA, adequacy countries and approved standard contractual clauses, including UK-approved clauses.
• Security assurance. Published assurance includes ISO 27001 certification, a SOC 2 Type II attestation from July 2025 audited by Schellman, open-source clients, a bug bounty and a vulnerability disclosure programme — among the strongest documentation in this class.
• Support in UK hours. Support is published as 24/7 for all business customers with phone support for organisations of six or more users and a dedicated account manager on Enterprise, which compares well against similarly priced suites.
• Desktop and calendar workflow gaps. Bridge provides desktop mail access, but Proton Calendar does not sync to Outlook or Google Calendar; UK teams with entrenched desktop habits should trial this specific workflow before committing.
• Collaboration limitations. Distribution lists replace shared mailboxes, groups cannot be used in Calendar or Drive, and meeting participant caps apply — confirm these against your established support and collaboration processes.
• Migration scope. Easy Switch covers mail, contacts and calendars from any IMAP provider, Gmail, Yahoo or Outlook; plan file and application-data migration separately, since no Drive or Teams file tool is documented.

Proton prices per user monthly in US dollars, euros or Swiss francs, with annual billing discounts: Workspace Standard at $14.99 ($12.99 billed annually) covering Mail, Calendar, Drive, Docs, Sheets, Meet, VPN and Pass with 1 TB per user, and Workspace Premium at $24.99 ($19.99 billed annually) adding Lumo, retention policies and 3 TB per user. Product-specific plans range from $1.99 to $11.99 per user monthly.

Minimum user counts apply on product plans — Drive Professional and VPN plans require at least two users, Pass plans at least three — and a 14-day free trial plus a 30-day money-back guarantee reduce commitment risk. Payment methods include card, PayPal, bank transfer and, unusually, Bitcoin.

No sterling price exists anywhere on the published surfaces, so the effective UK cost moves with the exchange rate and card charges. Extra custom domains cost $1.50 per user per month beyond plan limits.

• No sterling price list and no UK data residency. Billing exists only in dollars, euros and Swiss francs, and hosting sits in Switzerland, Germany and Norway — both routine procurement hurdles for UK organisations without explicit sign-off.
• Mail lacks SSO and SCIM. Single sign-on and directory provisioning exist only for VPN and Pass; Proton Mail does not support them and groups cannot sync to an identity provider.
• No shared mailboxes. Proton offers distribution lists instead, which will not satisfy support-desk or accounts-inbox patterns that depend on a genuinely shared mailbox with common sent items.
• Calendar does not sync to Outlook or Google. Desktop calendar workflows stay inside Proton, and Bridge covers mail only, so teams with entrenched Outlook calendar habits face a behavioural change.
• No documented file migration tool. Easy Switch covers mail, contacts and calendars; migrating Drive or Teams files requires manual planning or a specialist mover, which extends project timelines.
• Encryption depth varies by path. Zero-access encryption protects stored mail, but external incoming mail is briefly readable and email metadata cannot be encrypted — facts Proton documents itself that should shape expectations.
• Meeting and collaboration caps. Participant limits of 100 or 250, two simultaneous active meetings, and unusable groups in Calendar and Drive constrain heavier collaboration patterns.