Your OneDrive can look almost empty and Microsoft can still say your storage is full, because OneDrive isn’t the only thing using it. On a free Microsoft account, 5 GB of cloud storage is shared by your OneDrive files and photos, your Outlook.com attachments, and files from other Microsoft apps. Large email attachments, the OneDrive recycle bin, Loop workspaces and Designer projects all count. Start by opening the storage breakdown in your Microsoft account; it usually shows the culprit straight away.
You have two separate quotas
Microsoft splits a personal account’s space into two buckets, according to its storage quotas page:
- Mailbox storage holds your Outlook.com emails, contacts and calendar items.
- Cloud storage holds your email attachments plus your files and photos in OneDrive.
| Plan | Mailbox storage | Cloud storage |
|---|---|---|
| Free (no subscription) | 15 GB | 5 GB |
| Microsoft 365 Basic | 100 GB | 100 GB |
| Microsoft 365 Personal | 100 GB | 1 TB |
| Microsoft 365 Family, Premium or Pro | 100 GB per person | 1 TB per person (up to 6 people) |
That’s why a nearly empty OneDrive can still be “full”: the warning is about cloud storage, and your attachments are in it. If the message says Microsoft Unified Storage is full, Microsoft’s Outlook.com help confirms it’s the cloud storage quota you’ve gone over.
Step 1: See what’s using the space
Open the Microsoft storage section of your account dashboard and sign in. It shows your quota and how much each part is using. For the mailbox side, open Outlook.com and go to Settings > Account > Storage, which breaks usage down by folder.
Step 2: Check the usual suspects
Email attachments, including the ones you sent. Attachments live in your cloud storage, and you can’t delete an attachment on its own: Microsoft says you have to delete the email it’s attached to. In Outlook.com, sort your folders by size (Filter > Sort by > Size) and don’t forget Sent Items. After deleting those emails, also delete them from Deleted Items.
The OneDrive recycle bin. Files you’ve deleted from OneDrive still count until they leave the OneDrive recycle bin, where they stay for up to 30 days on a personal account. Emptying the Recycle Bin on your PC doesn’t help: Microsoft notes you have to empty the OneDrive one online. Once a file is gone from there, it can’t be restored, so check before you empty it.
Large files you forgot about. OneDrive can list your largest files. Microsoft suggests looking for ZIP archives and checking whether your camera roll backup is full of videos, screenshots and images saved from social media.
Loop and Designer. Both count toward the same cloud storage. In Loop, delete workspaces, pages and ideas you don’t need, then empty each workspace’s own recycle bin. In Designer, open My projects and review recent projects and generated images. Designer has no recycle bin, so anything you delete there is gone for good.
A folder someone shared with you. Microsoft lists this as a reason a personal OneDrive can go over its limit: a shared folder you added to your OneDrive can push your own account over. Microsoft’s help on a full OneDrive points to removing the shared folder from your OneDrive in that case.
An expired plan or promotion. If your Microsoft 365 subscription expired or failed to renew, your storage quota changed with it, and Microsoft says you need to renew to get the same amount of storage again. The same happens when the 100 GB Samsung bonus or another promotion ends; Microsoft notes those were for a fixed period and can’t be renewed.
A common move that won’t help
Outlook.com’s help suggests saving attachments to OneDrive and then deleting the original email. That frees up mailbox space. But since attachments and OneDrive files both count toward the same cloud storage, moving a file from one to the other doesn’t reduce your cloud usage; deleting it does.
Step 3: Give it a day
After you delete files, Microsoft says it can take up to 24 hours for your quota to update. If the number still hasn’t moved, check the storage figure on the OneDrive website or in Outlook.com’s Email storage section.
What happens if you stay over the limit
Microsoft lists the consequences on its storage quotas page:
- OneDrive: you can’t upload, edit or sync new files, including camera roll backups. Existing files stay, but they’re read-only.
- Outlook.com: you can’t send or receive email if you’re over either quota. Messages sent to you bounce back to the sender, who has to resend them once you’ve made room.
- Microsoft Teams: you can’t send or receive messages with attachments.
- After three months over your OneDrive limit, your OneDrive account is frozen. After six months, Microsoft might delete your OneDrive and everything in it, and deleted files can’t be recovered.
When paying for more space makes sense
If you’ve cleared the obvious waste and you’re still close to 5 GB, the data is simply bigger than the free plan. The smallest step up in Microsoft’s table is Microsoft 365 Basic, which raises both your mailbox and your cloud storage to 100 GB. If you need more than 100 GB for files, the Personal, Family, Premium and Pro plans include 1 TB of cloud storage per person.
This guide covers personal Microsoft accounts. Work and school accounts have different quotas set by the organization, and the fix there starts with your IT administrator.