New preparers tend to think of due diligence as a checkbox at the end of the return. It is not. It is the record of the questions you asked, the answers you got, and why those answers were reasonable.
When a preparer gets a due diligence letter, the request is almost never about the client. It is about the file. What did you ask? What did you keep? What made you comfortable?
Write the question, not just the answer
A note that says head of household confirmed is worth very little. A note that says who lived in the home, for how many months, and who paid more than half the cost of keeping it up is worth a great deal. Same conversation, completely different file.
What a defensible file usually holds
- Your intake, dated, with the client answers in their own words.
- The follow-up questions you asked when something did not line up.
- What documents you reviewed, and what you did not review.
- Notes on anything unusual, and why you were satisfied with the answer.
Contemporaneous beats comprehensive. A short note written the day of is worth more than a long one written a year later.
None of this slows you down once it is built into your workflow. It only feels heavy when you try to reconstruct it after the fact.