I need reassurance. I am trying to check APRs with the OCC APR checker software. I have a 12-month construction-only loan, multiple advance, interest-only payments monthly, with a balloon at maturity. Am I correct that I have to calculate the interest by hand, using Addpendix D of Reg Z, then input that? Is the # of unit periods "1"? If inspection fees are collected up front, then they are prepaid f/c and not subsequently paid fees?

Boy...just what I needed before vacation... a "Z" problem.

Just do the whole calculation with Appendix D. If you've estimated the interest, the rest is very easy.