
Are you struggling to manage your data in Microsoft 365? Do you want to avoid losing your data, violating regulations, or wasting storage space? If so, you need to know the differences between retention, archive, and backup. These are three data management options that can help you protect your data, comply with rules, and optimise your performance. But what are they exactly, and how do they work? In this article, I will answer these questions and more. I will explain the main features and benefits of each option, along with any risks involved. I will also provide some scenarios where you might want to use one or more of these options and how Microsoft solutions can support you.
Introduction
Retention, archive and backup are three concepts that are often confused or used interchangeably in data management. However, they have distinct purposes and implications for organisations that must comply with various regulations, policies and best practices. To make sure that your Microsoft 365 data is safe and accessible at all times, it’s essential to understand how retention, archive, and backup work together. By using these options effectively, you can ensure that your data is always available when you need it.
What is Retention?
Retention and records management is the practice of managing the retention and deletion of your organisation’s data to meet legal, regulatory, and business needs. You can apply retention policies to different types of data in Microsoft 365, such as emails, documents, and chat messages. In addition, you can use policies to control the lifecycle of your data by deleting data when it is no longer required.
Retention and record management examples
You might need to retain your content for legal and compliance purposes:
- Use a retention policy to keep all emails in all user mailboxes for seven years and then delete
- Use record labels to keep contracts until ten years after the contract ends and then go through a disposition review before deletion.
- Use a retention policy to keep critical Team and Sharepoint site data for one year, then release the retention.
On the other hand, you may need to ensure that data gets deleted to minimise risk:
- Use a retention policy to delete all chat messages after three months to follow your company policy.
- Use a retention policy to delete an ex-employee Teams chats after one month and emails after one year.
Retention and record management benefits
- Compliance: Comply with regulations and avoid fines or lawsuits
- Data security: Protect your important data from accidental deletion or corruption
- Data lifecycle management: Retention policies help you manage your data efficiently by controlling its lifecycle.
- Cost savings: Retention policies help you reduce storage costs by deleting data when it is no longer required.
- Risk management: Retention policies help you mitigate risks associated with data loss or corruption.
What is Archiving?
Archive is the process of moving your data that is not actively used to a separate storage location, where it can be retrieved if needed. Archiving policies are typically applied to data with long-term value or historical importance that is not frequently accessed or modified. These policies can also specify how long you want to keep the data and what to do with it afterwards.
Archiving examples
You might want to archive for historical, reference or audit purposes:
- All project teams that were closed more than 2 years ago to be archived for 10 years.
- All historical information about the building or plant construction or other company matters to be kept indefinitely.
- All teams or sites that have not been accessed in the last year, thus freeing up SharePoint sites.
Archiving benefits
- Reduce operational costs: Archiving helps you reduce operational costs by freeing up space on your primary storage and optimising its performance.
- Compliance: Lomg term retention of inactive data to meet regulatory and compliance needs
- Preserve historical data: Archiving helps you preserve historical data with long-term value or historical importance.
What is Backup?
Backup is the process of creating immutable copies of your data stored in a separate location, allowing for easy restoration in case of data loss or corruption. With backups, you can recover from accidental or malicious deletion, corruption or ransomware attacks. Backup policies can be applied to critical data necessary for business continuity or disaster recovery ensuring a quick and accurate restoration. These policies also specify how long the backup data needs to be retained. Third-party solutions can perform backups which integrate with Microsoft 365. Microsoft has recently announced its own backup solution which will be launched soon.
Backup examples
For example, you may use a backup to:
- Backup critical SharePoint sites used for business operations and keep the backup copies for five years
- Backup all user mailboxes and keep the backup copies for one year.
Backup benefits
- Data recovery: Recover from accidental or malicious deletion, ransomware attacks, hardware failures, or natural disasters
- Business continuity: Ensure that your critical data is available when you need it, even in the event of a disaster or disruption.
- Compliance: Comply with various regulations such as NIS2 that require you to keep your data safe and accessible
- Peace of mind– Create a separate immutable copy of your data
Comparison
The following table summarises the benefits, challenges and risks of each option:
Retention | Archive | Backup | |
---|---|---|---|
Purpose | Retain the content that you need to keep, and delete the content that you don’t. | Preserve historical & inactive data | Immutable copy of your current data that is kept for disaster recovery in case of data loss or corruption. |
Use | Ensure data is retained or deleted in line with company policies or regulatory compliance. E.g. GDPR and deleting personal data when it is no longer required. It is not designed to protect data from cybersecurity attacks. | Long-term retention for legal, compliance or historical purposes. Moving inactive data to lower-cost cold storage. | To restore operational data to its original state after a disaster |
Storage Location | Hidden copies of data retained in Microsoft 365 | Data moved to cold storage | A copy of the data in immutable storage |
Benefits | Helps you comply with legal and regulatory and compliance requirements Actively manage the data lifecycle to keep what you need and delete the rest Ensure users work only with content that’s current and relevant to them Reduce storage costs when used with a deletion action | Long-term retention for legal, compliance or historical purposes. Moving inactive data to lower-cost cold storage. | Protects against data loss or corruption Guarantees data recovery Ensure data availability Gives you flexibility and control over your backup frequency, retention and restoration |
Challenges | Define retention policies for different types of data Apply retention policies consistently across the organisation Monitor and audit retention activities Consumes SharePoint storage space Data restore is complex Automated labelling required E5 information protection and Governance licencing. | Requires investment in third-party solutions or native tools Define archive policies for different types of data Apply archive policies consistently across the organisation Ensure accessibility and security of archived data May have limited functionality compared to the primary mailbox or storage location | Requires investment in third-party solutions or native tools Define criticality of data to define restore priorities |
Risks | Does not protect against data loss or corruption Accidental data loss when data is deleted that needed to be retained. Retention takes priority over deletion so it can impact the right to be forgotten. | Does not protect against data loss or corruption Increased storage costs for archiving unnecessary data | Does not help you comply with legal and regulatory requirements Restore speeds based on the volume of data |
How does Microsoft Support retention, archive and backup
Microsoft Purview Data Lifecycle Management and Records Management (required E5 Compliance or E5 Information Protection and Governance)
Microsoft Purview offers retention policies for various data types, including email, documents, chat messages, etc. These policies allow organisations to determine if data should be retained, deleted after a specific period, or retained and then deleted.
Retention policies can be applied to the entire organisation or specific locations. Additionally, retention labels can be applied manually applied to individual items. Default and auto labelling options are available with the E5 Information Protection & Governance license.
Microsoft records management is a feature that helps organisations manage their data lifecycle, compliance, and legal obligations. It allows users to apply retention labels to documents, emails, and other items, and automatically delete or preserve them based on predefined policies. Records management also provides tools to review and dispose of records that are no longer needed or have reached their end of life.


Microsoft reference documentation: Learn about Microsoft Purview Data Lifecycle Management | Microsoft Learn
Archive mailboxes
Microsoft 365’s archiving feature, also known as In-Place Archiving, offers users additional storage space for their online mailboxes. When a user’s archive mailbox is enabled, they gain access to an extra 100 GB of storage. If a user requires more than 100 GB, they can activate auto-expanding archiving, which provides up to 1.5 TB of extra storage in archive mailboxes. Though the primary mailbox and archive mailbox are separate, they are both connected to a single user.

Microsoft reference documentation: Learn about archive mailboxes for Microsoft Purview | Microsoft Learn
Microsoft 365 Archive (Public preview should begin in Q4 2023)
Microsoft 365 Archive provides a solution for inactive or ageing SharePoint sites to be moved to Azure for long-term ‘cold’ storage. This is a more cost-effective approach, which helps in freeing up your SharePoint ‘hot’ storage for active data. Additionally, it offers search and discovery functionality along with data security and compliance controls. This feature allows organisations to archive or reactivate sites in place without migrating data outside of the Microsoft ecosystem. Reactivated data retains all original permissions, labels, and metadata.

Microsoft reference documentation: Welcome to Microsoft Inspire 2023: Introducing Microsoft 365 Backup and Microsoft 365 Archive – Microsoft Community Hub
Microsoft Backup (Public preview should begin in Q4 2023.)
Microsoft 365 Backup enables organisations to securely backup and restore their OneDrive, SharePoint, and Exchange Online data. It offers fast backup and restore speeds and provides a restore SLA. Moreover, it comes equipped with advanced search and filter capabilities, allowing users to easily locate content in backups using metadata.
In the unfortunate event of a ransomware attack, Microsoft 365 Backup helps you restore your data to a healthy point in time, ensuring that your company’s content can be recovered exactly as it was before the attack. This feature helps keep your data safe and secure, giving you peace of mind knowing that your organisation’s critical information is protected.

Microsoft reference documentation: Welcome to Microsoft Inspire 2023: Introducing Microsoft 365 Backup and Microsoft 365 Archive – Microsoft Community Hub
Can Microsoft Purview retention policies be used in place of backup and archive?
It’s important to note that while Microsoft Purview retention policies can help you manage your data, they are not a substitute for archive or backup. If you are considering whether they can replace the need for backups, it’s essential to understand that retention policies don’t create a separate copy of your data and don’t offer any guarantees for data recovery, nor do they provide you with the flexibility to control your backup frequency, retention, and restoration. They simply help you retain the content that you need to keep for compliance purposes and delete the content data that is no longer needed to reduce risk. The data under retention remains in Microsoft 365. On the other hand, archive is used to preserve historical and inactive data by moving it from Microsoft 365 to cold storage to release capacity for active content. This frees up expensive SharePoint storage for new and active content. Backup, on the other hand, creates an immutable copy of your current data that is kept for disaster recovery in case of data loss or corruption.
Conclusion
Data is the backbone of any organisation, and safeguarding it is essential to keep your business running smoothly. Retention, archive, and backup tools empower you to achieve this objective effectively. By leveraging them in tandem, you can ensure that your data is easily accessible and compliant while inactive data is archived to reduce storage costs. Additionally, data backups are crucial for disaster recovery and business continuity. With the right tools and approach, you can keep your data secure, compliant, and accessible at all times, and focus on achieving your business goals with peace of mind.