Business email and office suites · Comparison
Microsoft 365 Business vs Proton for Business
2 products compared side by side: what you pay for with each one first, then the five access facts, entry prices, recorded plan limits and the bottom line of each review. The evidence note under the table says how each product was checked.
Side by side
| Metric | Microsoft 365 Business | Proton for Business |
|---|---|---|
| What you're paying for | Worth the priceA 100 GB Exchange mailbox, 1 TB of OneDrive and Office for the web per user from $5.40 a month, with desktop Office apps one plan up. | Compliance includedEnd-to-end encrypted email and calendar on your own domain, with 1 TB per user, Docs, Sheets and recorded meetings on Workspace Standard. |
| Overall score | 7.6Best | 6.4 |
| Free option | 30-day free trial | 14-day free trial |
| Card to start | Card required | –Not measured |
| Getting access | Self-serve | Self-serve |
| Starter priceCheapest paid plan | $5.40/user/mo | $6.99/user/mo |
| Pricing model | Per seat | Per seat |
| Pricing page | Public prices | Public prices |
| Billing unit | Per user per month; up to 300 users across all Business plans | Per user per month; storage pooled across Mail and Drive |
| Free option | No free plan; one-month trial for up to 25 users, credit card required | No free plan on a custom domain; 14-day trial for up to 10 users, payment method needed; 30-day money-back guarantee |
| Reference scenario (5 users, annual) | $27/mo on Business Basic (no Teams) ($5.40 × 5), computed; $35 with Teams | $64.95/mo on Workspace Standard ($12.99 × 5), computed |
| Month-to-month price | $6.48 per user on Business Basic (no Teams); $8.40 with Teams | $14.99 per user on Workspace Standard ($7.99 / $24.99 for Essentials / Premium) |
| Storage per user | 100 GB mailbox + 50 GB archive and 1 TB of OneDrive (1.5 TB archive on Premium) | 15 GB (Mail Essentials), 1 TB (Workspace Standard), 3 TB (Premium), pooled |
| Domains, aliases and catch-all | Up to 5,000 domains, 300 to 400 aliases per user; no catch-all stated | 3, 15 or 20 domains (extra $1.40/mo on Workspace); 10 or 20 addresses per user; catch-all |
| Office apps | Office for the web and mobile on Basic; desktop apps from Standard | Proton Docs and Sheets in the browser on every plan |
| Video meetings | Teams for 300 with recording in the plans with Teams | Proton Meet for 100 for 24 hours with local recording on Workspace Standard |
| Retention and eDiscovery | Litigation hold and eDiscovery export on Premium ($22); archiving add-on $3 | Retention policies on Workspace Premium; no eDiscovery |
| SOC 2 / ISO 27001 | Office 365 in SOC 2 Type II and ISO 27001 scope (Service Trust Portal) | SOC 2 Type II (report on request) and ISO 27001 |
| HIPAA BAA | Included in the data protection addendum by default | Offered to all users, signed on request by email |
| EU data storage | EU Data Boundary for EU and EFTA sign-ups | Swiss jurisdiction; no region choice stated |
| SAML SSO | Single sign-on for apps with Entra ID on every plan | Not supported for Proton Mail yet |
| Mailbox export | PST from classic Outlook per user; admin eDiscovery export on Premium | Per user with the Export Tool (EML and JSON); no admin export of all mailboxes |
| Bottom line | From its public pages, Microsoft 365 gives a large mailbox and 1 TB of OneDrive per user at a low price, with shared mailboxes, an audit log and a BAA on Business Basic. Retention and eDiscovery sit on Premium or add-ons, and refunds and seat cuts are limited to 7 days. | From its public pages, Proton for Business is the encryption-first option here, with audits, a BAA on request and a 30-day guarantee. The scenario needs Workspace Standard at $64.95 for five, and SSO, admin-wide export and a mail API are not offered. |
Evidence: Microsoft 365 Business: facts checked 2026-10-16 from its public sign-up and pricing pages, no completed hands-on run; Proton for Business: facts checked 2026-10-16 from its public sign-up and pricing pages, no completed hands-on run. Prices in USD as listed, excluding tax. "–" means not recorded.
When to pick each
In the words of each review, with the date its facts were checked.
From our Microsoft 365 Business review
Checked Oct 16, 2026- Pick Microsoft 365 Business when
- You need SAML SSO, a mail API, shared mailboxes or the EU Data Boundary.
- Pick Proton for Business when
- You want mail encrypted end to end by default and a 30-day money-back guarantee.
From our Proton for Business review
Checked Oct 16, 2026- Pick Proton for Business when
- You want encryption by default and seats you can reduce at any time for credit.
- Pick Microsoft 365 Business when
- You need shared mailboxes, SSO or the EU Data Boundary, or a lower price ($27 for five on Business Basic without Teams).
Entry price
Baseline: each product's cheapest paid plan, per month. Included usage differs, so read the line under each price.
- Microsoft 365 BusinessBusiness Basic (no Teams)$5.40/user/moAnnual commitment; $6.48 month to month
- Exchange mail on your domain, 100 GB mailbox + 50 GB archive
- 1 TB of OneDrive per user
- Word, Excel, PowerPoint and Outlook for web and mobile
- No Teams meetings
- Proton for BusinessMail Essentials$6.99/user/moBilled annually; $7.99 month to month; $6.49 on 24 months
- 15 GB per user, pooled across Mail and Drive
- 3 custom domains, 10 addresses per user, catch-all
- Proton Docs and Sheets
- Meet for 50 for up to 1 hour
Prices as listed on each pricing page, in USD per month, excluding tax. Observed: Microsoft 365 Business 2026-10-16, Proton for Business 2026-10-16.
Which one fits
- If you need to start today without a sales call
- Microsoft 365 BusinessSelf-serve sign-up, card required; the highest score of the 2 self-serve products here (7.6/10).
- Lowest starter price
- Microsoft 365 Business$5.40/user/mo for the Business Basic (no Teams), annual commitment plan.
- Highest overall score
- Microsoft 365 Business7.6/10 (Good). The review shows the score breakdown and the run behind it.
Picked by fixed rules from the table above, not by hand. How we score
Full reviews
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