Did Microsoft recently change the storage quota of older OneDrive accounts?

I've noticed something rather strange with my OneDrive storage quota, and I'm curious whether anyone else has seen the same behaviour.

My account had 15 GB of OneDrive storage for many years.

Then, earlier this year, the quota unexpectedly increased to 30 GB. I documented this change on August 9, 2026, when I was investigating some OneDrive issues and noticed Microsoft's move towards the unified Microsoft Cloud Storage system.

I did not purchase Microsoft 365 or activate a temporary storage promotion or phone backup offer to obtain the additional storage. The account simply showed 30 GB.

Now, months later, the quota has unexpectedly gone back to:

30 GB → 15 GB

This is not just a cosmetic change. I currently have approximately 23.8 GB stored in OneDrive, so the account is now showing roughly 159% of the available storage, and OneDrive has stopped synchronizing new files.

I have screenshots documenting both the previous 30 GB quota and the current 15 GB quota.

What I find particularly interesting is the timing. Microsoft has been consolidating storage under the Microsoft Cloud Storage model, which includes OneDrive and other Microsoft services. Could changes to that system be affecting how older/legacy storage quotas are being assigned to accounts?

I'm not assuming that this is necessarily the cause — I'm interested in finding out whether other people have experienced similar quota changes.

Has anyone else seen an older OneDrive account change from 30 GB back to 15 GB recently?

Or perhaps experienced other unexpected changes to a legacy storage allowance?

I'm particularly interested in hearing from users who have had their accounts for many years and had storage above the current standard allocation.

I've also opened a support case with Microsoft, so I'm trying to understand whether this is an isolated account issue or something affecting multiple users.

Screenshots of the previous 30 GB quota and the current 15 GB quota are attached.