Microsoft runs the platform. Your data recovery is still your responsibility.

Microsoft's own Service Agreement advises customers to regularly back up their content and data stored in Microsoft 365. Many organisations have not read that clause closely — and current Australian cyber insurance questionnaires increasingly ask about independent SaaS backup.

See where the shared-responsibility line sits
What this covers

The shared-responsibility model in plain terms; native retention windows per workload across Exchange, OneDrive, SharePoint and Teams; six scenarios where native retention does not bring the data back; how cyber attack reaches Microsoft 365 data; what the current insurance questionnaire actually asks for; and how Microsoft 365 backup posture is assessed inside broader recovery work. This page is for organisations that run mail, files and collaboration inside Microsoft 365 and need to understand what an independent backup is there to protect against.

Quick answers

What Microsoft provides, what native features do not cover, and what a defensible posture looks like.

Question

Does Microsoft back up Microsoft 365?

No, not in the way most organisations assume. Microsoft operates the platform, keeps the service running, and replicates data across datacentres for resilience — it does not back up customer data with the intent of restoring it after deletion, cyber attack, admin error or malicious insider activity. Microsoft's own Service Agreement advises customers to back up their content.

Question

What does Microsoft provide natively?

Short-term retention and recycle bins across Exchange, OneDrive, SharePoint and Teams. Version history for recent changes. Litigation holds through Purview for compliance. Geo-redundancy for platform resilience. Useful short-term recovery tools — not a backup in the sense insurers, auditors and recovery plans use the word.

Question

What should a defensible posture look like?

Independent backup stored outside the tenant, under separate credentials with MFA, covering Exchange, OneDrive, SharePoint, Teams and Entra ID objects where supported. Immutable storage, retention well beyond native windows, granular restore, and dated restore-test evidence — mapped to the specific Microsoft 365 questions on current insurance questionnaires.

Where the line sits

Microsoft keeps the cloud running. Your organisation keeps its data safe.

Microsoft 365 operates under the SaaS shared-responsibility model. The boundary between Microsoft's responsibility and the customer's is not ambiguous; it is explicitly documented by Microsoft and reinforced in the Service Agreement.

Microsoft's responsibility
Operational commitments met through service-level agreements
  • Physical datacentre infrastructure and network
  • Platform availability and service-level uptime
  • Geo-redundancy across datacentres
  • Hardware redundancy
  • Disaster recovery of the underlying platform
Protects against: hardware failure, datacentre outage
Your responsibility
Shown as customer responsibility in Microsoft's SaaS matrix
  • Customer data and content
  • Identities and access management
  • Endpoint configuration
  • How long to retain content and how to protect it
  • Backup, restore capability and recovery evidence
Protects against: deletion, attack, admin error, insider

"We recommend that you regularly back up Your content and data that you store on the Services." — Microsoft Services Agreement

Microsoft replicates data across datacentres for resilience — this protects against hardware failure and datacentre outages. It does not protect against user deletion, admin error, malicious encryption or tenant-wide misconfiguration. The replica is Microsoft's failover copy, not the customer's backup.
Native retention

Short-term retention, recycle bins and version history. Useful, but not a backup.

Microsoft 365 includes several built-in protections against routine data loss. Each has a defined window, scope and limit. Understanding what each one covers is the first step in understanding what they do not. The distinction that matters: native retention is designed for routine user error; backup is designed for non-routine loss events. The two are not substitutes for each other.

Exchange Online14 days default, up to 30

Deleted mail moves to Deleted Items, then to the Recoverable Items dumpster. Default retention is 14 days, extendable to 30. A removed mailbox is retained around 30 days by default. After the window expires, native recovery is not available.

OneDrive30 days plus 93-day recycle bin

User-deleted files go to the Recycle Bin. If a user account is removed, OneDrive data is retained 30 days (admin-adjustable), then placed in the Site Collection Recycle Bin for an additional 93 days. Version history is retained per configured policy.

SharePoint OnlineTwo-stage recycle bin

Site Collection Recycle Bin with similar two-stage retention. SharePoint-backed file recovery requires admin involvement once items leave the user recycle bin, and full-site restore is a more complex operation than per-item recovery.

Microsoft TeamsSharePoint- and Exchange-backed

Teams files sit in SharePoint and follow SharePoint retention. Channel messages and chat history live in Exchange under compliance storage. There is no user-facing Teams recycle bin, and team deletion recovery is time-limited.

Microsoft Purview holdsCompliance, not backup

Purview supports litigation holds and retention policies for compliance — useful to prevent deletion for legal discovery. They are not backups: the data sits inside the tenant, is accessible to administrators with the right privileges, and does not protect against the scenarios a backup is designed to address.

Where native features do not cover

Six scenarios where native retention does not bring the data back.

Every scenario below is documented in Australian renewal reviews and post-incident investigations. These are not edge cases — each is a case where native retention expires, is bypassed, or was never designed to cover the outcome.

01
Accidental deletion discovered beyond the retention window

A file accidentally deleted 120 days ago in OneDrive or SharePoint is gone — the two-stage recycle bin tops out at 93 days, and an email purged more than 30 days ago cannot be retrieved through native tools. Discovery often lags deletion by months, especially for files rarely accessed until they are needed.

02
An attacker encrypting files in OneDrive, SharePoint or Teams

A cyber attack reaching Microsoft 365 through a compromised session encrypts files. Microsoft's replication copies the encrypted state across datacentres. Version history helps only where the attack is caught quickly and pre-encryption versions still exist; where the window has expired or the attacker has disabled versioning, recovery is not possible without an independent backup.

03
Compromised global administrator with time to cause damage

A global admin compromise allows mailbox deletion, site deletion, Teams destruction and retention-policy modification to accelerate permanent deletion. Microsoft does not provide a tenant-wide rollback. An independent backup stored outside the tenant under separate credentials is the control for this scenario.

04
Malicious insider activity before or during departure

A departing employee with legitimate access can delete mail, files and records; a dissatisfied admin can clear retention policies and trigger permanent deletion. Native retention assumes the actor is acting in error — deliberate destruction is outside the design intent of the feature.

05
Configuration errors that propagate before detection

A misconfigured policy, a bad migration script, a bulk operation that affected more than intended — these are replicated across Microsoft's redundant systems as normal state. There is no undo button at the tenant level; restoring requires granular work through the admin centre within retention windows, or an independent backup.

06
Graph API throttling on large restores

Restoring large volumes through the Microsoft Graph API hits throttling limits. A month of email across a hundred mailboxes recovered through eDiscovery can take substantially longer than an incident response timeline accepts. Backup products restoring through dedicated APIs and pre-indexed storage are not subject to the same throttling.

The current threat reality

The assumption that SaaS is immune to cyber attacks has not aged well.

The early assumption was that cloud-hosted productivity data was outside the cyber attack threat model. The threat has adapted. Attacks that reach into Microsoft 365 data are now common enough that Australian insurance questionnaires increasingly ask about independent backup scope. The entry vector is usually an account compromise rather than a direct attack on Microsoft infrastructure: a stolen session token from an endpoint, a phished administrator credential without phishing-resistant MFA, or a malicious OAuth application granted broad tenant permissions. Each gives the attacker operational access to the same data the user would see, at the same permission level.

From there, the attacker can encrypt files through the authenticated session, modify retention policies, disable versioning, or simply delete content. Microsoft's platform-level defences do not prevent an authenticated user from performing actions the user is authorised to perform — that is not a Microsoft failure; it is the consequence of an authenticated compromise. Encrypted files inside Microsoft 365 are replicated by Microsoft's infrastructure as normal customer activity. In practice, discovery often happens days or weeks after the encryption run, by which time recoverable versions are gone or the attacker has disabled versioning as part of the attack chain.

A common pattern: the organisation discovers encrypted files across OneDrive and SharePoint. The IT team attempts recovery through recycle bins and version history. Partial recovery succeeds for recent or high-version files; significant quantities of older or single-version files cannot be recovered. When an underwriter asks whether the organisation has independent backup of Microsoft 365 data, the question is not hypothetical — it comes from claims history where the native retention did not hold up.

Insurance questionnaire territory

The question is now on the questionnaire. The answer needs to map to evidence.

Microsoft 365 backup is a recurring category on Australian cyber insurance renewal questionnaires. The specific questions vary by underwriter, but the pattern is consistent.

Questionnaire item

Do you have an independent backup of your Microsoft 365 data?

A "yes" requires a backup operated outside the tenant, under separate credentials. A "yes" that relies on native retention is typically scored as a gap, because the underwriter knows native retention is not what the question is asking about.

Questionnaire item

What is the scope, retention period and backup cadence?

Which workloads (Exchange, OneDrive, SharePoint, Teams, Entra ID), which retention (years rather than the 14-to-93-day native windows), and which cadence (typically multiple times daily). A vague scope answer signals the backup may not match the claim.

Questionnaire item

When was the last documented restore test?

A dated record of a real restore, with scope and outcome documented — the evidence that separates a backup that would work under pressure from one that has never been tested. Many organisations have the backup and have never performed the restore test.

Questionnaire item

Is the backup admin separate from the Microsoft 365 admin?

Backup admin accounts must be separate from Microsoft 365 global admin accounts, with independent MFA, not sharing credentials with the daily operational identity. Otherwise a Microsoft 365 admin compromise reaches the backup.

Microsoft 365 backup is no longer a technical posture question. It is a commercial readiness question tied to renewal pricing, claim integrity and the evidence trail that determines whether coverage applies.

If your renewal answer on Microsoft 365 backup relies on native retention, it will likely be scored as a gap. A short review confirms independent coverage, credential separation and restore evidence before the questionnaire lands.

Review your M365 backup
Posture characteristics

Four characteristics that turn an assertion into evidence.

Stored outside the Microsoft 365 tenant

Independent of the tenant, under separate credentials with independent MFA, so a tenant-wide compromise does not reach the backup. The primary control against the cyber-attack and compromised-admin scenarios.

Coverage scoped to match the environment

Exchange, OneDrive, SharePoint, Teams and Entra ID objects where the product supports them — not partial coverage where one workload is backed up and another is assumed covered by native retention.

Retention aligned to real recovery scenarios

Measured in years rather than days, set against long-discovery deletion, cyber attack with a discovery lag, malicious insider activity uncovered months later, and regulatory or contractual evidence windows.

Restore testing documented on cadence

A dated restore-test report with scope, procedure, outcome and issues noted — produced often enough that the report on file is current when an insurer or auditor asks. This is what converts the backup from an assertion into evidence.

How this fits

Part of the broader recovery position, not a standalone purchase.

Microsoft 365 backup is one category in a broader recovery architecture. It connects to backup architecture, identity recovery sequencing, dependency modelling, and the evidence layer that current insurance questionnaires increasingly require. Where the broader question is "could we recover from a destructive cyber event with evidence that holds up at renewal," Microsoft 365 backup posture is usually assessed inside a Recovery Readiness Assessment rather than as a standalone problem. Where Microsoft 365 backup is the specific area that needs attention and the rest of the recovery position is already understood, the work can be scoped directly within Backup and Disaster Recovery.

Inlight IT view

The Inlight IT view on Microsoft 365 backup.

Microsoft keeps the cloud running. Your organisation keeps its data safe. That sentence is closer to Microsoft's own Service Agreement than most buyers realise, and more directive than most buyers read it as. Where organisations usually have work to do is in three places: independent backup coverage that matches the actual workload scope rather than a partial implementation; backup administrator credentials separated from Microsoft 365 administrative credentials with independent MFA; and dated restore-test reports that turn the backup from an assertion into evidence.

None of these is exotic or expensive relative to the cost of a loss event, and all three are commonly absent until a structured review surfaces them. Independent recovery capability is the benefit; the cost of a dedicated third-party backup service, and the operational discipline to run it, is the trade-off.

A backup that exists is not the same as a recovery path that works. The difference matters most on the day it is tested by an attacker.

Worth checking

If Microsoft 365 holds your contracts, finance mail and client records, the shared-responsibility line is worth a one-hour check, not an assumption.

Check your side of the line →
From the work

Microsoft 365 backup work in practice.

As an illustration rather than a headline: in one property-development environment, Microsoft 365 backup posture was reviewed as part of the broader recovery position rather than as an isolated product purchase — independent backup coverage across Exchange, OneDrive, SharePoint and Teams, credential separation from the Microsoft 365 administrative identity, retention aligned with insurance-questionnaire expectations, and restore-test evidence. The point of the example is the framing: Microsoft 365 backup treated as one part of a recovery whole, not a standalone tick-box.

Frequently asked

Questions Australian organisations ask about Microsoft 365 backup.

Does Microsoft back up Microsoft 365?
No, not in the way most organisations assume. Microsoft operates the platform, keeps the service running, and replicates data across datacentres for resilience. It does not back up customer data with the intent of restoring it after accidental deletion, cyber attack, admin error or malicious insider activity. Microsoft's own Service Agreement advises customers to back up their content. Native retention windows and recycle bins are short-term recovery tools, not a backup.
How long does Microsoft retain deleted data?
It varies by workload. Exchange keeps deleted mail in Recoverable Items for 14 days by default, extendable to 30; a removed mailbox is retained around 30 days. OneDrive retains a user's data 30 days after account removal, then in the Site Collection Recycle Bin for an additional 93 days. SharePoint follows the same pattern. Version history is retained per policy. After these windows expire, native recovery is not available.
What does the shared-responsibility model actually say?
In the SaaS model Microsoft 365 operates under, Microsoft is responsible for physical infrastructure, network, platform availability and service resilience. The customer is responsible for data, identity and access management, and endpoint configuration. Microsoft's own documentation shows customer data and identities as customer responsibility, and the Service Agreement reinforces it directly: customers are advised to regularly back up their content and data.
What happens to Microsoft 365 data in a cyber attack?
A cyber attack that reaches Microsoft 365, usually through an authenticated session or compromised credential, can encrypt files in OneDrive, SharePoint and Teams, and can disable versioning or modify retention policies as part of the attack. Microsoft's replication copies the encrypted state across datacentres as normal activity. Version history can help if the attack is caught quickly and pre-encryption versions still exist; in practice, recovery often requires an independent backup stored outside the tenant.
What does an independent Microsoft 365 backup cover?
A defensible scope usually covers Exchange mailboxes, OneDrive, SharePoint sites, Teams content and Entra ID objects where the product supports them. The backup is stored outside the tenant, under separate credentials with independent MFA, on immutable storage where possible, with retention measured in years. Restore capability is granular — individual item recovery, not only full-tenant restore — and restore tests are performed and documented on cadence.
Do cyber insurance questionnaires ask about it specifically?
Increasingly, yes. Current Australian renewal questionnaires commonly include specific questions about SaaS data backup, with Microsoft 365 named explicitly. Underwriters want to know whether an independent backup exists, its coverage scope and retention period, and whether restore testing has been performed with dated evidence. An answer that relies on native retention is typically scored as a gap.
Is litigation hold in Purview the same as a backup?
No. Litigation hold and retention policies in Purview are compliance tools that prevent deletion of specified data beyond its normal retention window for legal discovery. They are not backups: the data sits within the tenant, is accessible to administrators with the right privileges, and does not protect against malicious encryption, admin error or tenant compromise. Useful for compliance; not a substitute for independent backup.
What if an admin account is compromised and wipes our data?
An administrator compromise can result in mailbox deletion, site deletion, Teams destruction, and retention-policy modification to accelerate permanent deletion. Microsoft does not provide a tenant-wide rollback. The control is an independent backup stored outside the tenant under separate credentials, with backup administrator identity isolated from Microsoft 365 administrative identity. Without that separation, a Microsoft 365 admin compromise can reach the backup itself.
What about Microsoft 365 Backup, the Microsoft service?
Microsoft now offers a Microsoft 365 Backup capability for selected workloads and restore scenarios, creating backups within the protected services' data boundaries. It should still be assessed against your requirements for independence, credential separation, retention, immutability, restore testing, licensing and recovery evidence. The question is whether the recovery path meets your incident, audit and insurance requirements — for some it closes the immediate gap, for others it sits alongside an independent third-party backup rather than replacing it.
How do we assess our current backup posture?
Microsoft 365 backup posture is usually assessed inside a Recovery Readiness Assessment, which covers current backup coverage, credential separation from the tenant, retention configuration, restore-test evidence, and the specific Microsoft 365 questions on current insurance questionnaires. Where the assessment identifies gaps, remediation is sequenced alongside other recovery priorities rather than treating Microsoft 365 backup as a standalone problem.
Practical next step

Make Microsoft 365 backup posture defensible — for renewal, for audit, for recovery.

A short review maps native retention against the scenarios you carry, confirms independent backup coverage and credential separation, and turns the backup into dated evidence.

Review your Microsoft 365 backup posture