See example 6:

https://www.federalregister.gov/documents/2018/11/07/2018-24411/tax-return-preparer-due-diligence-pe...

The preamble makes it pretty clear that even if you already know, you still have to ask and document the responses.

"The new Example 6 clarifies that a tax return preparer who possesses pre-existing knowledge that was acquired outside the context of the preparer's tax return preparation practice cannot meet the knowledge requirement of paragraph (b)(3)(ii) by relying on that pre-existing knowledge. The tax return preparer must make reasonable inquiries to determine the applicable facts, and the inquiries and responses to those inquiries must be contemporaneously documented in the tax return preparer's files."

Or if no money changes hands, go with Terry's solution.

Rick