Hey there, thank you for reaching out!

Only users with a verified student account can collaborate on files located in an Education team.

I’m afraid it’s not possible to have a mix of paid members on the Professional plan and free members on the Education plan.

For more context, our plans are team-specific and not account-wide, so files located on an Education plan team can only be edited by users who have verified their education status, and files located on a Professional plan team can only be edited by users who have a paid “full” seat on that team.

I’m linking this article from our Help Center, which has some helpful guidance on how to collaborate with other users: Guide to collaborating with clients in Figma.

So regarding your question “If I want to address the exposure of the above phrase, do I need to upgrade my account that created the design to a professional team account? Does the other developer need to upgrade their account information?”

The education status is only available for students or educators who meet the qualification criteria for the Education plan. If you believe the developer meet the criteria, they can apply for the education status here: https://www.figma.com/education/apply.
Alternatively, you would need to create a professional account to collaborate.

Please let me know if this clears your question, or if you have any further questions, happy to help out!

Thank you,
Gayani