Question: what are the due diligence requirements?
Answer: Complete and Submit Form 8867. Complete Form 8867, Paid Preparer's Due Diligence Checklist, for each return or claim for refund you preparer that claims EITC, CTC/ACTC/ODC, AOTC and/or HOH filing status. ... 
Compute the Credits Based on the Facts. ... 
Ask All the Right Questions. ... 
Keep Records.