If your SharePoint tenant is over quota, you have a decision to make: keep paying Microsoft’s storage overage, move cold files into Microsoft 365 Archive, or hand them to a third-party archiving tool. This is a straight Microsoft 365 Archive vs third-party archivingcomparison — no vendor hand-waving, just what each approach costs in 2026, where Microsoft’s built-in tier genuinely wins, and the three catches (a four-month re-archive lockout chief among them) that decide whether your cold data should stay inside Microsoft’s walls or move somewhere cheaper and portable.
What Microsoft 365 Archive actually is
Microsoft 365 Archive is a cold-storage tier built into Microsoft 365. It started as a site-level feature — you archived an entire SharePoint site, which then went dormant. It now also does file-level archiving: individual documents move to the archive tier while the site stays live. Per Microsoft’s documentation, file-level archive is enabled by default once Microsoft 365 Archive is turned on, and archived content stays searchable.
Archived data still lives in Microsoft’s storage, but it’s billed at a lower rate (more on that below). The trade-off is retrieval: an archived file has to be reactivated before it opens normally, which takes time to rehydrate rather than the instant open of a file that never moved. For genuinely cold files — the finance exports from 2021 nobody has touched since — that’s a non-issue. For anything you might actually need on a Tuesday afternoon, it matters.
The pricing: $0.05/GB/month — and when it’s genuinely cheaper
Microsoft 365 Archive charges US$0.05 per GB per month for archived storage, and crucially, that meter only runs when your archived plus active storage exceeds your tenant’s licensed quota. If you’re still under quota, archiving costs nothing extra (Microsoft’s pricing documentation lays out all five billing scenarios).
Put concrete numbers on it. Say 3 TB of cold files are sitting above your tenant quota. Left as-is on the Office 365 Extra File Storage add-on at US$0.20/GB/month, that’s roughly US$615 a month. Move the same 3 TB into Microsoft 365 Archive at US$0.05/GB/month and it drops to about US$154 a month — the four-times saving in a single line. Archiving the same data out to object storage drops it further again: our own rate is A$29 per TB per month for managementwith a bring-your-own bucket, with storage billed directly at your provider’s list price. The gap between the three widens every month your data grows.
Compare that to the alternative of doing nothing: the standard Office 365 Extra File Storage add-on runs about US$0.20 per GB per month (it varies by region and purchase channel). So Microsoft 365 Archive is roughly four times cheaper than paying the overagefor the same data. That’s a real saving, and for a certain kind of tenant it’s the right call:
- You’re only modestly over quota and don’t want another vendor in the stack.
- Your archived data is truly cold and you can live with reactivation latency.
- You want everything to stay inside Microsoft’s compliance and eDiscovery boundary, full stop.
For those cases, the built-in tier is a sensible, low-friction win. But “four times cheaper than the overage” is not the same as “the cheapest way to store cold data” — and the gotchas below are why.
The gotchas: the four-month lockout, tenant lock-in, and latency
Three catches separate Microsoft 365 Archive from a clean cost solution. None are dealbreakers on their own; together they shape when the built-in tier stops being the obvious answer.
1. The four-month re-archive lockout
Microsoft removed the per-GB reactivation fee for SharePoint archives on 31 March 2025 — good news. But there’s a string attached: once you reactivate archived content, you can’t re-archive it for four months. Pull a site or file back into active storage and it sits there, counting against your quota at full rate, for the rest of the quarter. If your access patterns are lumpy — quarter-end reporting, an audit, a project that briefly reopens old material — that lockout can quietly erase the savings.
2. Tenant lock-in and no exit path
Archived data never leaves Microsoft’s storage. There’s no bring-your-own-bucket option, no way to point the archive at cheaper object storage, and no portable copy you can walk away with. Your cold data’s cost is permanently tied to Microsoft’s per-GB rate and your tenant’s quota maths. That’s fine until the rate changes or your data grows faster than your licences do.
3. OneDrive is treated differently
The reactivation-fee removal applies to SharePoint only. Archived, unlicensed OneDrive accounts are still billed per GB to reactivate, per Microsoft’s pricing docs — worth knowing if leaver accounts are part of your storage problem.
When third-party archiving wins
Third-party archiving tools — ArchiveBridge included — take a structurally different approach: instead of moving cold files to a cheaper tier inside Microsoft, they move them out to object storage and leave a small stub link in SharePoint pointing to the new location. That one architectural difference is where the wins come from:
- Object storage is far cheaper per GB. You can bring your own Wasabi or Backblaze B2 bucketat published object-storage rates and pay the archiving vendor for management only — no per-GB storage markup, and no dependence on Microsoft’s quota economics.
- The data actually leaves the quota. Once a file is verified in the bucket and the original is removed, it no longer counts against your SharePoint pool at all — not at $0.05, not at anything.
- No re-archive lockout.Restore a file, use it, let it age out again on your own schedule. There’s no four-month penalty box.
- Integrity is provable.A good tool hashes every file, confirms the copy byte-for-byte before deleting the original, and logs it. ArchiveBridge does exactly this — SHA-256 verify-before-delete, one mismatch halts the job. That’s the whole reason to trust a move-then-delete pipeline; see how the archive pipeline verifies every file before removal.
- There’s a real exit path. Copies sit in your bucket, under your keys, in standard S3 object format. Leaving means restoring in bulk and disconnecting — no negotiation to get your own data back.
The honest trade-off runs the other way here, and it’s worth stating plainly. A third-party tool is another vendor and another admin consent to manage. And because the data physically leaves SharePoint, it sits outside Microsoft’s native compliance domain — Microsoft’s own documentation notes that keeping data in place lets eDiscovery, retention, and search tooling operate seamlessly, which is a real advantage of the built-in tier. A well-built archiving tool compensates by staying Purview- and legal-hold-aware and excluding held content automatically, but “compensates” is the operative word: if your compliance posture depends on everything living inside Microsoft’s boundary, that weighs for Microsoft 365 Archive.
So the split is clean. If your only concern is a small overage and you want zero new moving parts, Microsoft 365 Archive is the simpler call. If cold data is a large and growing line on your bill, the economics tilt hard toward archiving outside the tenant — and the savings compound.
Microsoft 365 Archive vs third-party archiving: the decision framework
Strip it down to a few questions:
- How far over quota are you? A little, and shrinking? Microsoft 365 Archive is the low-effort fix. A lot, and growing? Object-storage archiving pays for itself faster every month.
- How lumpy is access?Predictably cold data suits Microsoft’s tier. Data you reopen unpredictably runs into the four-month lockout — advantage third-party.
- Do you care where the bytes live?If control, portability, and per-GB cost matter, bring-your-own-bucket archiving wins. If staying 100% inside Microsoft is a hard requirement, it doesn’t.
- What’s the three-year picture? Data never shrinks. Model the compounding cost before you commit — our transparent per-terabyte pricing is built for exactly that comparison.
These two aren’t the only options, either — for the wider field, including ShareArchiver, Squirrel, ShArc and AvePoint Opus, see our honest comparison of SharePoint archiving solutions.
You can’t make this call on principle — you make it on your own numbers. The fastest way to get them is a free, read-only tenant scan: it shows how many gigabytes of aged files you’re paying premium rates to keep, and what moving them would save, before anything moves at all. Take that figure to Microsoft 365 Archive’s pricing and to ours, and the honest comparison stops being theoretical.