Can I cancel an NCE subscription after I've committed to it?

It depends on timing. Microsoft provides a limited cancellation/change window shortly after purchase (historically within the first several days) during which you can cancel or reduce an NCE subscription without penalty.

After the window closes

• Monthly-term subscriptions generally continue to the end of the current billing cycle.
• Annual-term subscriptions typically cannot be canceled early without a cancellation fee, since you've locked in pricing for the full term.

If you're unsure whether you're still inside the change window for a specific subscription, your CSP partner can check this for you directly in the admin portal — it's time-sensitive, so it's worth asking sooner rather than later.