Having a loan app signed is not a regulatory requirement. Investors may require it. I had one unsigned that I did a loan on. The military officer filed bankruptcy and neither his app nor his credit report showed 1/3 of his debts. Because there was nothing that said his statements were "true and correct", counsel said he never lied about his debts.
I'd recommend getting an app signed, but it isn't required and won't happen if the loan is denied and you never see the applicant. So definitely mark it "by phone" as this helps on GMI and joint intent as well.
My opinions are not necessarily my employers.
Rules and Regs minus Relationships equals Resentment and Rebellion. John Maxwell