STOP PAYING FOR YOUR CLIENT'S EDR TWICE

Your Business Premium clients already own an EDR. A lot of MSPs sell them a second one anyway.

Business Premium includes Defender for Business, Defender for Office 365 Plan 1, Entra ID P1, and Intune. Microsoft held it at $22 a user in July 2026 while Business Standard went from $12.50 to $14. If you still run SentinelOne or Cylance on those clients, your client pays for endpoint protection twice and your techs run two stacks.

The answer isn't "Microsoft for everything." Your security stack has three layers: the EDR, the 24/7 SOC, and email filtering. Each one gets a different answer. This guide covers all three, the math, and when not to switch. If you want help building the plan for your own book, Schedule a Call.

THE EDR: STANDARDIZE ON DEFENDER FOR BUSINESS

What your client already paid for

Defender for Business gives you EDR, automated investigation and response, attack disruption, and core vulnerability management. One user license covers five devices. Servers need their own license at $3 per server, up to about 60 servers.

What the duplicate costs you

I modeled both stacks per seat per month. The third-party stack (SentinelOne, an MDR, identity monitoring, an email filter, and security awareness training) runs about $15. The Microsoft-native stack with the same MDR, identity monitoring, and training runs about $7. That's roughly $8 a seat you stop paying for. Every extra laptop or VM widens the gap. SentinelOne bills per endpoint. Defender for Business bills per user. These are modeled numbers built on list prices and community-reported MDR rates. Run them against your own contracts before you take them to a client.

What it did at an MSP I work with

One MSP I work with standardized on Defender. Service margin went up about 2%. License resale margin dollars went up too, riding Microsoft's price changes.

THE SOC: KEEP IT

Business Premium has nobody watching at night

Business Premium includes no 24/7 monitoring. Practitioners report Defender alerts sitting unread over weekends. Automated investigation in semi-automatic mode contains a threat and then waits for somebody to approve the fix.

Your MDR still installs its own agent

Huntress, Blackpoint, ConnectWise MDR, and Sophos all work with Defender. Huntress and Blackpoint still deploy their own agent next to it. So the Microsoft path removes SentinelOne or Cylance, not every third-party agent. Your MDR bill stays about the same.

Why that independence matters

When you consolidate, one tenant holds identity, email, endpoint, and the tools that detect attacks on all three. An attacker with Global Admin weakens the controls built to catch him. Storm-0558 and the 2025 Entra actor token flaw showed tenant-level compromise is real. An MDR with its own agent and console gives you eyes outside the tenant. Defender replaces your antivirus. It doesn't replace your night shift.

EMAIL: TEST BEFORE YOU DROP YOUR THIRD-PARTY FILTER

The evidence disagrees

Microsoft's own benchmark says third-party tools caught an extra 0.06% to 1.11% of total mail as malicious. One r/msp data set from a tuned Business Premium setup across about 100 users says about 45% of malicious messages got past Microsoft. Microsoft published its own numbers. The second-layer vendor in the r/msp test decided what counted as malicious. Neither one is independent.

Run your own test

Set Defender for Office 365 to Microsoft's strict preset on a few tenants. Run it next to your current filter for a set period and count what each one catches. Keep a second layer for clients where one missed email turns into a wire fraud loss: finance, legal, real estate, and title.

THE MONEY: WHO PAYS FOR THE UPGRADE

The $8 uplift barely touches your margin

Moving a client from Standard at $14 to Premium at $22 adds $8 a seat to their bill. At a 5% license margin you keep about 40 cents of it. Your gain comes from the tools you remove.

Even if you absorb it, you come out ahead

If you eat the $8 to hold the client's total flat, you still come out about $1 a seat ahead in the model. And the client gets device management, Conditional Access, and data protection that cost $34 a seat bought separately on Standard.

Sell ownership, not the brand swap

Intune policies, Conditional Access, and Defender settings live in the client's tenant. If they leave you, they keep that work. That lowers their cost to leave, so your MDR, tuning, reporting, and insurance evidence become the reason they stay. Price those. Don't price the license.

WHEN NOT TO SWITCH

Hold off, or fix something first, when:

The client has more than 300 users or more than about 60 servers.
They handle CUI or ITAR data. Move them to GCC or GCC High first.
Their insurer gives a credit tied to a named non-Microsoft MDR, worth more than your tool savings.
A big share of endpoints run macOS or Linux and you haven't tested Defender on them.
Your team lacks Intune, Conditional Access, and ASR skills. An untuned Defender tenant is worse than a working SentinelOne deployment.
The SentinelOne or email contract has more than six months left and exiting costs more than you save.

None of these needs a second EDR. They need a different license, an add-on, or more time.

HOW TO ROLL IT OUT

Set a license floor

Publish a date when Business Premium becomes required for new and renewing clients. Defender for Business standalone at $3 a user works as a short bridge for Basic and Standard tenants. It's not a destination.

Pilot, then baseline

Run it on your own tenant first, then two or three friendly clients. Pull tickets per endpoint and security hours per agreement before you start. Without a before picture, you won't prove the switch paid off. If you don't know those numbers today, start with the Operational Maturity Assessment.

Time the cutover to renewals

Line up each switch with the SentinelOne, Cylance, and email renewals and the client's Microsoft anniversary. Annual seats don't drop after the 7-day window. Export SentinelOne uninstall passphrases before you cancel, or you'll rebuild machines to get the agent off.

YOUR NEXT MOVE

If the stack never got standardized because every decision runs through you, that's the real problem. Take the MSP Owner Reality Check and see where else the business is waiting on you. Or Schedule a Call and we'll build the plan for your book.

FAQ

Does Defender for Business replace my MDR?

No. Business Premium has no 24/7 monitoring. Keep an independent MDR. Huntress, Blackpoint, ConnectWise MDR, and Sophos all work with Defender.

Is Defender for Business good enough to replace SentinelOne?

For most Business Premium clients under 300 users, yes, as long as you tune it, push one baseline, and keep a SOC on top. The exceptions are CUI work, heavy macOS or Linux fleets, and clients past the 300-user or 60-server limits.

Should I drop my third-party email filter?

Not until you test it. Microsoft's data and community data disagree, and neither is independent. Run both side by side on a few tenants, then pick one standard for your whole book.

STOP PAYING FOR YOUR CLIENT'S EDR TWICE

Your Business Premium clients already own an EDR. A lot of MSPs sell them a second one anyway.

Schedule a Call