For small and mid-sized businesses, the real question is rarely E3 vs. E5 – it's Business Premium vs. E3. Both give you Office apps, mail, and Teams, but they target different company sizes and needs. Know the difference and you often pay less for more.
The decisive difference: the 300-user cap
The most important fact first: Microsoft 365 Business Premium is capped at 300 users. Microsoft confirms this in the Business Premium FAQ – the 300-user cap applies to the entire Business family (Basic, Standard, Premium) combined. The Enterprise plans (E3, E5) have no such limit.
- Under 300 employees and without specific enterprise requirements, Business Premium is usually the cheaper, more feature-dense choice.
- At 300 employees and beyond – or when you need enterprise features – there's no way around E3/E5.
What makes Business Premium strong
Business Premium is not a "stripped-down" plan – quite the opposite. For SMBs it packs a lot of security into an affordable bundle:
- Office apps (desktop + web), Exchange, Teams, SharePoint, OneDrive.
- Defender for Business – endpoint protection that's included in Business Premium and, on the Enterprise plans, only arrives with E5 (or as an add-on).
- Device and app management (Intune), Conditional Access, and data protection features.
For an SMB that wants solid protection without enterprise complexity, this is a very dense package at a low price.
What E3 offers instead
E3 is the entry point into the enterprise world:
- No 300-user cap – it scales without limit.
- Advanced enterprise capabilities for compliance, management, and identity.
- A seamless path to add E5 building blocks as your needs grow.
E3, however, does not automatically include the endpoint protection that Business Premium brings – on the Enterprise side, that only comes with E5 or as an add-on.
The comparison table
| Criterion | Business Premium | Enterprise E3 |
|---|---|---|
| User cap | max. 300 | unlimited |
| Office apps & core services | ✓ | ✓ |
| Endpoint protection (Defender for Business) | ✓ included | – (only E5 / add-on) |
| Enterprise compliance & scale | limited | ✓ |
| Target audience | SMBs up to 300 | mid-market & enterprise |
Feature scope and the 300-user cap follow the current Microsoft product description – see the Office 365 plan options (as of early 2026).
The classic cost trap
Many growing SMBs land on E3 or even E5 out of habit or on someone's recommendation – even though they're under 300 users and would be cheaper and better protected with Business Premium. Conversely, some stay on Business Premium long after they've grown past 300 users, then patch things together inconsistently.
The mistake is rarely the initial choice – it's failing to re-adjust when size or needs change.
How to make the right decision
- Count your actual users. Under 300? Business Premium is in the running.
- Assess your security needs. Do you need endpoint protection? Business Premium includes it; on Enterprise it costs extra.
- Check for enterprise requirements. Advanced compliance, very large scale? Then E3/E5.
- Check what you actually pay for and use today. Mixed estates from old decisions often keep running.
That last point is exactly what License Lens makes visible: connect your tenant in read-only mode and see, per assignment, which plan is actually being used and where a switch saves money – in seconds, with no employee data stored.
The bottom line
Under 300 users, Business Premium is the smarter choice for most SMBs: more protection, lower price. E3 pays off when you cross the cap or genuinely need enterprise features. Review regularly whether your plan still fits your company size – real money is riding on it.
Next: E3 vs. E5 · the most common cost traps.