Welcome to our news!
September's Partner Center updates point at one shift: how partners get paid and how customers pay. Growth margins moved from sandbox to production APIs, a week before launch. A new consumption offer construct, the Flex Spend Plan, landed in sandbox. And the new Copilot arrived with a two layer commercial model: user subscriptions plus usage-based billing.
TL;DR:
- Growth margins went live on October 1, 2026. The eligibility and discovery APIs are in production since September 23, and the M365 E5, E7, and Copilot promotions ended September 30. Call the eligibility API before every qualifying order.
- Flex Spend Plans are in sandbox since September 1. One commitment covers multiple Azure services with monthly billing. Test purchase, billing, and reconciliation flows now.
- The new Copilot combines Home, Code, and Autopilot. User subscriptions cover everyday work, and usage-based billing covers advanced capabilities. No CSP action yet, but the billing conversation with customers starts now.
Here are the announcements that matter most for CSP partners this month.
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Microsoft Updates - [09/2026]
Summary Table
| Update | Date | Who's Affected | Action Required |
|---|---|---|---|
| Validate eligibility for CSP growth margins through APIs | APIs live September 23, 2026; growth margins GA October 1, 2026 | CSP distributors and direct bill partners | Yes |
| New CSP sandbox offer construct preview (Flex Spend Plan) | Sandbox available since September 1, 2026 | All CSP segments, SSPs, SDCs, and GSIs/SIs | Yes |
| Introducing the new Copilot | Announced September 25, 2026; rolling out through the Frontier program | All partners | No, prepare customer conversations |
Validate eligibility for CSP growth margins through APIs
What's happening: Microsoft opened early production access to growth margin discovery and eligibility ahead of the October 1 launch. Partners can validate customer eligibility through the eligibility API and download eligible SKUs and minimum seat requirements from the Pricing workspace in Partner Center.
Date of Announcement: September 23, 2026
Effective Date APIs and Pricing workspace download: September 23, 2026, 00:00 UTC. Microsoft 365 E5, Microsoft 365 E7, and Copilot promotions ended: September 30, 2026. Growth margins generally available: October 1, 2026 (already in effect).
Who is affected: CSP distributors and direct bill partners. Growth margins apply only to these two partner types.
Action Required: Yes. Call the eligibility API before submitting qualifying transactions, and check the cart line item and review page for the growth margin. Update quotes that relied on the E5, E7, or Copilot promotions that ended September 30.
💡 Quick Note: Ineligibility doesn't block the order. It just drops the transaction to standard margin, without warning anyone. So the API call belongs inside the order flow, not in a one off check. Watch the mid-term trap too: seat additions on an existing subscription never qualify, so incremental seats need a new subscription to earn the margin. The full rules are in Growth margins.
New CSP sandbox offer construct preview (Flex Spend Plan)
What's happening
Microsoft made a storage and database test product, the Flex Spend Plan, available in the CSP sandbox. One Flex Spend Plan covers multiple eligible Azure products and services under a single commitment, with monthly billing instead of full upfront payment and auto-renewal. Microsoft plans to use the same construct for several future consumption products.
Date of Announcement: September 2, 2026
Effective Date: Sandbox available since September 1, 2026. No production date announced yet.
Who is affected: All CSP segments (direct bill, indirect resellers, distributors), SSPs, SDCs, and GSIs/SIs integrating with the new offer type
Action Required: Yes. Integrate with the new offer type in sandbox, test the purchase, billing, and management flows, and identify the system or operational changes it requires. The sandbox product doesn't include trials, promotions, or incentives.
💡 Quick Note: Three details will hit billing and customer success teams first. Partners can't self-serve cancel a Flex Spend Plan. A customer moving to another CSP loses the commitment, and the new partner must buy a new one. And reconciliation and invoice data aren't in sandbox yet, so recon testing waits for a later sandbox update. Scope details and known issues are in Use Flex Spend Plans in Partner Center.
Introducing the new Copilot
What's happening
Microsoft introduced the new Copilot, which combines Home (Chat and Cowork with the full Office apps), Code, and Autopilot, a persistent cloud hosted agent, into one experience. The commercial model has two layers: user subscriptions for everyday Copilot value, and usage-based billing for advanced capabilities. FinOps for AI adds new ways to govern AI costs.
Date of Announcement: September 25, 2026
Effective Date: Rolling out through the Frontier program, with capabilities arriving continuously. The announcement doesn't include CSP SKU, pricing, or date details. I'm not sure about CSP transaction timing, please verify here.
Who is affected: All partners
Action Required: No immediate transaction required. Partners should get familiar with the user subscription plus usage-based billing model before customers ask about it.
💡 Quick Note: The pricing story is now two bills, not one. The user subscription license covers everyday AI work. Usage-based billing covers Cowork, Code, and Autopilot, consumes Copilot Credits, and still requires a user license. Customers will ask who owns that second bill, IT or the business unit. Partners who can answer it, and set up spending limits, own the expansion conversation. The model is explained in Understanding the user subscription license (USL) and usage-based billing (UBB).
The Bottom Line
September moved CSP economics from fixed to variable, on both sides of the invoice. Growth margins reward new-to-offer and expansion deals, but only when the order meets the rules at the moment of purchase. Flex Spend Plans and Copilot usage-based billing push customers toward commitments and consumption instead of flat seat counts. Partners who wire eligibility checks, consumption billing, and cost governance into their operations now will price deals with confidence while others reconcile surprises.
Source
All announcements sourced from the official Microsoft Partner Center announcements page: Microsoft Partner Center Announcements September 2026
