I don't have any personal experience in this area, but I agree with you. You should ask your loan officer why they would need social security numbers of minors that do not live with you. I can't see any legitimate reason that they would need it. You should also contact OHFA to ask them if THEY require SSNs of non-resident children. If OHFA doesn't require their SSNs and your loan officer won't back down, take your business to another bank. Plenty of other banks offer OHFA loans (they are listed on the OHFA website). Good luck!