Site archiving in SharePoint Online: how Microsoft 365 Archive works and where it fits in the site lifecycle
SharePoint sites and Teams keep multiplying but almost never go away. Microsoft 365 Archive moves them to cheaper storage and keeps permissions, metadata and searchability. What it needs, what it costs, what it can't do, and why it belongs at the end of the site lifecycle.
In most organisations, a new SharePoint site or team in Teams is easy to create: a project, an event, a tender, a working group. Nobody wants to remove one, though. The project ends, people leave, and the site stays. A few years on, the tenant has hundreds of sites, and for many of them nobody knows whether they are still needed.
Those sites are not harmless. They take up paid storage and clutter search results next to current documents. They often have open sharing that nobody reviews any more. And Copilot has added another worry: outdated documents can end up in its answers.
Nobody wants to delete them, “just in case”. But between deleting a site and leaving it to rot there is a third way: archiving. Microsoft offers a service for it, Microsoft 365 Archive. This article covers how it works, what it needs, what it costs and where it fits in managing the site lifecycle.
What Microsoft 365 Archive is
Microsoft 365 Archive is cold storage inside SharePoint. An archived site stays in the tenant with everything it contains — libraries, folders, files, lists, permissions and metadata. But you don’t pay for it as active storage, and users can’t access it directly.
| What changes after archiving | What stays |
|---|---|
| content is no longer directly accessible to anyone | permissions and all metadata |
| the site appears on the Archived sites page | searchability: regular Microsoft 365 search, Purview Content Search and eDiscovery |
| storage moves from the tenant’s active quota to the archive | retention policies, labels, holds and auditing |
| according to Microsoft, Copilot “is not trained on archived content” — so the archive doesn’t clutter its answers | data stays in the same geography and within the EU Data Boundary |
In practice: you will find a document from an archived site in search, but you can’t open it. An administrator first has to reactivate the site. After reactivation the site is back as it was before archiving — permissions, lists, pages and metadata included. The only exceptions are recycle bin items whose retention period expired in the meantime, and content that a retention policy deleted in the meantime.
What you need to archive
Microsoft 365 Archive isn’t on by default. It is billed on a pay-as-you-go basis through an Azure subscription:
- An Azure subscription and resource group to bill to.
- Pay-as-you-go billing set up in the Microsoft 365 admin center.
- Turn on archiving: Settings › Org settings › Pay-as-you-go services › Settings › Storage services › Archive and the SharePoint site archive toggle.
- Archive a site: in the SharePoint admin center, go to Active sites, select the sites and choose Archive. Archived sites then appear on the Archived sites page.
Sites can be archived and reactivated by a SharePoint Administrator or a Global Administrator. For bulk work there is PowerShell (Set-SPOSiteArchiveState) and Microsoft Graph (still in beta).
Microsoft explicitly recommends notifying site owners and users in advance that they will lose access. Technically that’s a detail, but in practice it decides whether archiving goes smoothly or ends in calls to the helpdesk.
What it costs
| Item | Price (Microsoft price list) |
|---|---|
| archived storage | USD 0.05 per GB per month |
| site reactivation | free (since 31 March 2025) |
| for comparison: extra active SharePoint storage | USD 0.20 per GB per month |
An important detail: the archive is charged only when archived and active storage together exceed the quota the tenant gets with its licences. If you stay within the quota, the archive costs nothing. If you exceed it, you pay only for the part of the archive above the quota — USD 0.05 per GB per month, a quarter of the price of extra storage. Microsoft’s cost calculator gives an estimate for your tenant.
Reactivation is free, but reactivated content can’t be archived again for four months. So archiving isn’t a switch to flip back and forth.
How archiving works
| State | What it means | What you can do |
|---|---|---|
| Recently archived | the first 7 days after archiving | reactivation is instant; the site can be deleted |
| Archived | after 7 days | reactivation takes up to 24 hours; the site can be deleted without reactivating it |
| Reactivating | reactivation in progress | the site can’t be deleted; once done it returns to the active sites |
The first seven days act as a safety net — if you notice you archived something by mistake, you get it back straight away.
What can’t be archived
- Publishing sites, channel sites and some older templates. Regular team sites (including Microsoft 365 group-connected ones), communication sites and several classic templates are supported.
- Hub sites — you first have to unregister them as a hub.
- Teams with private or shared channels. The admin center blocks archiving such a team. PowerShell or Graph will do it, but they archive only the main site; the channel sites stay active.
- For a group-connected site only the site is archived. The Microsoft 365 group stays active.
- OneDrive can’t be archived by an administrator. Some OneDrive accounts that have been unlicensed for 93 days or more are archived by the service itself and billed differently (including a reactivation fee).
Besides whole sites, Microsoft 365 Archive can also archive individual files. That has more limitations (some apps don’t yet handle archived files properly) and it’s a different decision — tidying up inside a live site, not the end of a site. We don’t cover it here.
Archiving is not retention
This gets mixed up a lot. A retention policy in Microsoft Purview says how long content must be kept and when it may be deleted — a legal and compliance obligation. Archiving is about where content lives, who can access it and what storing it costs.
The two work together: retention policies, labels and holds apply to archived content too, and eDiscovery finds it. But archiving doesn’t replace retention. An archived site without a retention policy can be deleted just like an active one.
Read-only, archive or delete?
| Read-only (locked) | Archive | Delete (e.g. by group expiration) | |
|---|---|---|---|
| users see the content | yes, but can’t change it | no, they only find it in search | no |
| storage | counts toward the active quota | moves to cheap archive storage | freed up — a deleted site doesn’t count toward tenant storage |
| way back | unlocked by an admin | reactivated by an admin, free | restore only within a limited window (93 days for a site, 30 days for a group) |
| when it fits | the site is done, but people still use it for reference | the content must be kept, but nobody works with it any more | the content has no value and retention doesn’t require it |
Watch out for Microsoft 365 group expiration in Microsoft Entra. It deletes an inactive group that its owner doesn’t renew — together with its site and team. For organisations that want to keep content, that’s the exact opposite of what they expect from archiving. It’s worth checking whether you have it turned on and how it’s configured.
Archiving is the end of the lifecycle, not the start
The Archive button alone won’t solve the problem of inactive sites. The hardest question is: which site should be archived? Only someone who knows the site can answer — its owner. And this is where most organisations get stuck: older sites often have no owner, the owner has left, or doesn’t know the site exists.
That’s why archiving only works as the last step of a well-designed site lifecycle:
- Created with an owner and a purpose. Every new site has an accountable person, a purpose and a type from day one. Sites created on the side that nobody claims are the number one source of zombie sites.
- A catalogue. A list of sites with owner, purpose, classification and expiry. Without it, you can’t tell what is still needed.
- Expiry and recertification. Every so often the owner confirms that the site is still in use — or that it has served its purpose.
- Watching for inactivity and ownerless sites. A site nobody has touched for a year, or whose owner has left, should be reviewed by someone.
- A decision based on the table above: lock, archive or delete. And a record of who decided and when.
What Microsoft offers
SharePoint Advanced Management (SAM) has three types of policies for the site lifecycle:
- Inactive sites — track activity in SharePoint, Teams, Exchange and Viva Engage and notify owners that a site is inactive. The owner can confirm with one click in the email that the site is still needed.
- Site ownership — find sites with too few owners. They can also notify the managers of former owners or active site members.
- Site attestation (periodic confirmation) — every 3, 6 or 12 months owners confirm that the site is needed and that its owners, members, permissions and sharing are right.
If the owner doesn’t respond to three notifications sent a month apart, a policy can set the site to read-only and, after 3, 6, 9 or 12 months, archive it through Microsoft 365 Archive (for the ownership policy, only sites with no owner at all). Policies can first run in simulation mode, which only produces a report.
You need a base licence (Office 365 E3, E5 or A5, or Microsoft 365 E1, E3, E5 or A5) plus SAM. You get the SAM features that support a Copilot rollout automatically once at least one user in the organisation has a Microsoft Copilot licence. Otherwise you need the SharePoint Advanced Management Plan 1 add-on or Microsoft 365 E7.
SAM, however, is mainly about monitoring and enforcement. It doesn’t handle requests for new sites, doesn’t record a site’s purpose or classification, and doesn’t make sure a site is created with an owner in the first place.
How we handle it
That part of the lifecycle is exactly what our Governed sites app covers. A new site or team is created only through a request and approval, and has an owner, purpose and classification from the first minute. You import your existing sites from the tenant and add their owner and expiry in the catalogue, so it also holds sites created before the app was rolled out. The app shows sites whose expiry has passed or is coming up, and an administrator sends the owner a reminder with one click. After agreeing with the owner, the administrator recertifies the site or extends its validity — or locks or archives it in the catalogue. The archiving itself in Microsoft 365 Archive is done by a SharePoint administrator, who now knows which site and why. Every step — request, approval, creation, lock, archive — stays in the change history.
This doesn’t rule out SAM policies. Governed sites makes sure every new site has an owner who can decide about it, and gives you a place to add one for existing sites. SAM then watches for inactivity and can archive automatically.
How to get started
- Take inventory. How many sites you have, how many are inactive and how many have no owner. The Active sites page in the SharePoint admin center or a SAM policy simulation gives you the first numbers.
- Work out whether the archive pays off. If you’re within your storage quota, the archive costs nothing. If you exceed it, compare the archive price with buying extra storage.
- Check retention and group expiration. So you know what may be deleted, what must be kept, and whether anything is being deleted on its own.
- Set the rules. When a site counts as inactive, who decides, when it gets locked and when archived. Write it down once, clearly.
- Turn on Microsoft 365 Archive and archive the first wave of sites manually, after notifying their owners.
- Govern new sites from the start. Without an owner and a purpose for new sites, you’ll be doing the same clean-up again in two years.
Key takeaways
- Microsoft 365 Archive keeps a site with everything — permissions, metadata, searchability and compliance — and moves it to cheap storage. You pay only above the tenant quota, and reactivation is free.
- It has limits: publishing sites, hubs, teams with private or shared channels, and groups that stay active after their site is archived.
- Archiving is neither retention nor deletion. Each of the three has its own tool and it pays not to mix them up — especially watch out for group expiration, which deletes content.
- Archiving only makes sense at the end of the lifecycle. If you don’t know who owns a site and what it’s for, you have nothing to base the decision on.
We cover site inventory, archive setup and lifecycle rules as part of our environment review and governance design. If you want to clean up your tenant and keep it that way, get in touch.
Sources: Microsoft Learn — Overview of Microsoft 365 Archive, Set up Microsoft 365 Archive, Manage Microsoft 365 Archive, Archive states, Microsoft 365 Archive pricing, Compliance in Microsoft 365 Archive, Pay-as-you-go pricing, SharePoint site lifecycle management, Inactive site policies, Prerequisites for SharePoint Advanced Management, Restore deleted sites, Set expiration for Microsoft 365 groups.