It is telling that a user with an enterprise Office 365 license cannot find the Copilot settings menu that others describe. This is not a user error, it is a licensing gate, plain and simple. If your organization has not purchased the specific Copilot add-on or the premium tier that includes it, the menu option simply does not appear. That means disabling Copilot suggestions is not a matter of toggling a preference; it is a matter of what your IT department has decided to pay for.
For this user, and for anyone in a similar position, the practical takeaway is frustrating but clear. The absence of the Copilot section in File > Options is not a bug or a missing feature that needs troubleshooting. It is a deliberate design choice by Microsoft to keep the interface clean for users whose licenses do not include Copilot. The company has no incentive to offer a disable switch for a feature you do not have. If you want control over Copilot's visibility, your real options are to ask your administrator to block the feature at the tenant level through Group Policy or to accept that the suggestions will remain in the context menu until your organization either buys into Copilot or explicitly removes it.
This situation highlights a deeper tension in modern enterprise software. The tools we use at work are increasingly governed by license tiers, not by user preferences. A feature that feels like a helpful addition to one person can feel like unwanted clutter to another, yet the ability to customize that experience is often locked behind an administrative account or a higher subscription fee. For the individual user, the message is simple: your control ends where your license begins. The most direct path to a Copilot-free Excel is not a settings change, it is a conversation with your IT team about what your organization has actually licensed and whether they can enforce a policy to suppress it.