OpenAI and Microsoft Sign Non-Binding MOU for Next Phase of Partnership

OpenAI and Microsoft have signed a non-binding memorandum of understanding covering the next phase of their partnership, the two companies announced in a joint statement published on September 11, 2025. A definitive, binding contract does not yet exist. The companies said they are "actively working to finalize contractual terms in a definitive agreement."

The statement is short — three sentences of substance — but its timing and its careful legal framing carry weight. This is the formal, on-the-record signal that one of the most consequential commercial relationships in the AI industry has entered a renegotiation, and that the parties have agreed in principle on the shape of what comes next without yet committing to enforceable terms.

What the statement actually says

The full text of the announcement, attributed to both companies jointly, reads as follows:

"OpenAI and Microsoft have signed a non-binding memorandum of understanding (MOU) for the next phase of our partnership. We are actively working to finalize contractual terms in a definitive agreement. Together, we remain focused on delivering the best AI tools for everyone, grounded in our shared commitment to safety."

Three claims, each doing distinct work. The first establishes that a new phase of the partnership exists and that both parties have put initials on a document describing it. The second concedes that the document is not yet a contract — the legally binding "definitive agreement" remains under negotiation. The third offers the public-facing rationale: continued collaboration on AI tools, framed around safety.

The statement also links to a related document, "Statement on OpenAI's Nonprofit and PBC," connecting the partnership renegotiation to OpenAI's ongoing corporate restructuring. That linkage matters. The Microsoft relationship and OpenAI's governance structure have moved in tandem throughout the company's history, and the joint statement makes clear that the two processes are part of the same moment.

Why "non-binding" is the operative word

The legal distinction at the center of this announcement is easy to overlook and important not to. A memorandum of understanding is an expression of intent. It signals alignment on goals and structure, but it does not by itself obligate either party to anything enforceable. When OpenAI and Microsoft say the MOU is non-binding and that contractual terms are still being finalized, they are telling the market, regulators, and customers that the definitive terms — the numbers, durations, equity arrangements, exclusivity provisions, and revenue-sharing mechanics that define the deal — remain open until the definitive agreement is signed.

That transparency cuts both ways. It reassures observers that the two companies have not reached an impasse: they agree on the framework for the next phase, and negotiations are active rather than stalled. At the same time, it flags residual uncertainty. Until the definitive agreement closes, the terms that will govern compute supply, product integration, IP arrangements, and financial returns for the next era of the partnership are not locked in.

For a relationship of this scale, that middle position — agreed in principle, unsigned in law — is a recognizable and deliberate waypoint. Companies announcing complex, high-stakes restructuring frequently sequence the announcement this way: an MOU first, definitive documentation later. The joint statement follows that playbook precisely.

Why this partnership matters

Context for why a two-paragraph announcement commands attention. Microsoft's partnership with OpenAI, in place since 2019, has been the commercial engine behind the modern generative AI boom. Microsoft's capital bankrolled the training runs that produced the GPT model series; Microsoft's Azure infrastructure delivers OpenAI's models to enterprise customers; OpenAI's technology powers Microsoft's Copilot product line. ChatGPT, Azure OpenAI Service, and Microsoft 365 Copilot all sit downstream of this single relationship.

That interdependence means any change in the partnership's terms propagates across the industry. Microsoft's cloud business, its enterprise AI positioning against Google and Amazon, and its consumer AI products all draw on access to OpenAI's frontier models. OpenAI, for its part, depends on Microsoft for the compute capacity that frontier model development requires. When the two companies renegotiate the foundation of that arrangement, the outcome shapes competitive dynamics across cloud infrastructure, enterprise software, and foundation model development.

The September 11 statement confirms that the partnership continues into its next phase rather than dissolving. Whatever specific terms the definitive agreement ultimately contains, the direction of travel is continuity.

The restructuring backdrop

The joint statement does not exist in isolation. Its own text directs readers to OpenAI's contemporaneous statement on its nonprofit and public benefit company structure. OpenAI has been reorganizing its corporate setup — a process that involves the original nonprofit and a public benefit corporation (PBC) — and a restructuring of that magnitude necessarily touches the Microsoft relationship, since Microsoft's investment, equity position, and commercial rights were negotiated under the prior structure.

The sequencing of the two statements on the same news cycle is itself information. By publishing a joint statement with Microsoft alongside its restructuring announcement, OpenAI signaled that its most important commercial partner is on board with the direction of the reorganization — at least at the level of a non-binding understanding. For outside stakeholders watching OpenAI's governance evolution, Microsoft's co-signature on the MOU functions as a signal of alignment from the party with the most financial exposure to the outcome.

What the companies are emphasizing publicly

The rhetoric in the statement is notably restrained. There are no model announcements, no compute commitments, no dollar figures, and no timeline for the definitive agreement. The companies chose to emphasize continuity of mission over specifics: "Together, we remain focused on delivering the best AI tools for everyone, grounded in our shared commitment to safety."

The word "remain" carries the load in that sentence. Its function is reassurance — the partnership's public purpose, as the companies frame it, is unchanged even as its legal architecture is rebuilt. The pairing of broad access ("AI tools for everyone") with safety is the standard framing both companies use when addressing audiences that include regulators, enterprise customers, and the general public.

What the statement does not do is equally telling. It does not describe the terms under negotiation. It does not say when the definitive agreement will be signed. It does not disclose what changes between the current arrangement and the "next phase." Those omissions define the news agenda from here: the definitive agreement, when it arrives, is where the substantive story — revised economics, restructured rights, new commitments — will be told.

What to watch next

The immediate milestone is the definitive agreement itself. When OpenAI and Microsoft sign it, the MOU's framework converts into enforceable contract terms, and the companies will face pressure to disclose at least the outline of what changed. Until then, the September 11 MOU stands as the formal record that both parties intend to extend their partnership into its next phase, on terms still being written.