Do you already own one of them?
Start in the Microsoft 365 admin centre. Microsoft's own pages say Defender for Business is included in Microsoft 365 Business Premium, and not in Business Basic or Business Standard. A company on Business Premium is comparing a product it already pays for against one it would buy on top. A company on Business Standard is comparing $36.00 per user per year against a Sophos quote.
Which is the EDR product?
Defender for Business is: EDR is included, with automated investigation and response in the licence. Sophos Endpoint is not: EDR is not offered, and Sophos's suspicious-event detections, case creation and live response arrive with its separate EDR and XDR licences. A Microsoft 365 company that buys Sophos Endpoint to replace Defender for Business gives up EDR unless it buys the Sophos EDR licence too. The Sophos pricing guide shows what those licences cost on Sophos's own AWS Marketplace listing, since sophos.com shows no prices.
What does Sophos add that Defender lacks?
Ransomware rollback. Sophos Endpoint includes it (included), Defender for Business does not (not offered), so with Defender your recovery from ransomware rests on your backups. Sophos also sells a managed detection and response service under the same brand, where Microsoft sells no 24/7 managed service for Defender for Business at all: its Defender Experts services attach to the enterprise suites. Neither product includes a security team watching alerts in the licence compared here.
| Product | EDR | Ransomware rollback | Device control | Patch management | macOS | Linux | Mobile | MSP multi-tenant |
|---|---|---|---|---|---|---|---|---|
| Included | Not offered | Included | Not offered | Included | Add-on | Included | Included | |
| Not offered | Included | Included | Not offered | Included | Add-on | Add-on | Included |
What do the labs say about each?
Both posted 6 out of 6 for protection in AV-Test's August 2026 business round, Microsoft as Defender Antivirus (Enterprise) and Sophos as Intercept X Advanced. In AV-Comparatives' first-half 2026 business test Microsoft scored 98.8% protection with no false positives; Sophos scored 98.3% with 2 false positives and was listed as not approved, because its performance impact score of 49.1 exceeded the test's limit of 40. In MITRE's evaluations Sophos detected 66 of 90 substeps on the default view of the 2025 round; Microsoft's latest default-view result is from the 2024 round, 67 of 80 of 80, and now sits outside our 18-month window. The lab results scorecard has every product's latest round.
The performance finding matters on older office PCs: AV-Comparatives measures the slowdown a product causes in everyday tasks, and Sophos was the only product in the round to fail that criterion.
What does each one cost, and how is it sold?
Defender for Business is $36.00 per user per year, licensed per user for up to five devices each, for up to 300 users, bought online or through a Microsoft partner. Sophos Endpoint has no published price on sophos.com: Sophos asks for a quote from its sales team or a partner, and its own AWS Marketplace listing is the only place it shows a figure, as 12-month contracts priced per user. Servers are extra with both: Microsoft sells a separate Defender for Business servers add-on, and Sophos requires a Sophos Workload Protection subscription for Windows Server and Linux.
Which suits a regulated business?
Neither vendor publishes an offer to sign a HIPAA business associate agreement for these products. Microsoft's BAA covers in-scope services, and its in-scope list does not name Defender for Business; Sophos lists HIPAA among its attestations but its pages do not say whether it signs a BAA. Sophos lists PCI DSS and CMMC mapping in its trust centre. A practice or contractor should ask both vendors in writing before buying.
Which should a Microsoft 365 company choose?
- On Business Premium, with someone technical in-house: keep Defender for Business. You own EDR already; spend the Sophos budget on backups and on someone to read the alerts.
- Ransomware recovery is the fear, and nobody will restore from backup under pressure: Sophos Endpoint for the rollback, and price the Sophos EDR licence alongside it so you do not lose detection.
- Nobody will read any alerts: neither. Compare the best MDR for small business ranking, where analysts are included, or pair Defender for Business with a managed service such as Huntress.
- Older PCs and a tight IT budget: Defender for Business, on the performance result and the price you can see.