Microsoft 365 doubles Exchange Online mailbox storage <—> here’s what changed
Microsoft has quietly rolled out one of the more useful updates to Microsoft 365 Business licensing this year: primary mailbox storage for Business Basic, Business Standard, and Business Premium has jumped from 50 GB to 100 GB per user, effective as part of the July 2026 pricing and packaging update.
What’s actually changing
Microsoft 365 Business Basic, Standard, and Premium: 50 GB → 100 GB
Standalone Exchange Online Plan 1: unchanged, still 50 GB
Exchange Online Plan 2, Microsoft 365/Office 365 E3, and E5: already at 100 GB, no change
Why it matters
A lot of organizations were buying Exchange Online Plan 2 purely to get past the 50 GB mailbox ceiling. With Business Basic, Standard, and Premium now including 100 GB natively, that upgrade path is no longer necessary for storage alone — Plan 2 is still worth it if you need its archiving or compliance features, but not just for space.
A few practical notes for admins
– The rollout isn’t instant. Microsoft has said it’s tenant-by-tenant, with backfill for Business SKUs expected to run through the end of September 2026. Check the Exchange Admin Center to confirm your tenant’s actual quota before assuming it’s live.
– The mailbox bump doesn’t apply to standalone Exchange Online Plan 1 — only to the Business bundles.
– This sits alongside broader July 2026 pricing changes across Microsoft 365 Business and Enterprise SKUs, so it’s worth reviewing your licensing mix as a whole rather than in isolation.
More storage buys breathing room, but it’s not a substitute for mailbox hygiene — large attachments and years of untouched mail will still slow down search and sync even with double the ceiling.
Sources: Microsoft Q&A threads on the change, cross-referenced with Microsoft’s official 2026 M365 Pricing and Packaging Updates page.
