If a business owner withdrawls $13,000 from his corporate account and $10,000 from his personal account, do you solely fill in Section 1 A with his personal information and list the 2 separate account numbers in Part II or do you fill in Section 1 A (front and back) with his personal info and his corporation info?

I would treat this as a multiple transaction with the same individual receiving all cash proceeds and complete Section 1 A with persosnal info and list the 2 separate account numbers in Part II.

The proper way to complete the CTR would actually depend on who is getting the benefit of the cash withdrawal from the business account. If it is for the benefit of the business, such as for petty cash, then the business should be shown in Part 1 Section A with the business owner shown on page 2, Part 1 Section A. If this is the case the simpler way to complete the CTR would be to show the owner on page 1, the business on page 2, check 1 b and c, and check box e in Section B.

If, on the other hand, you know that the owner benefitted from both withdrawals, you would only show him ad dgp indicated.

I agree with devsfan on how to fill out the CTR in both scenarios. You just determine who benefited from the cash withdrawal on the business account.