AJ - can you please evidence where in Pub 970 it states that the educational payments count in the year you pay them?
what publication 570 states (bottom of page 2)
"When figuring an education credit, use only the amounts you paid and are deemed to have paid during the tax year for qualified education expenses."
so your response is problematic to me because not only must the payment be paid in 2018, but is ALSO must be 'deemed' to have been paid in 2018. The college is 'deeming' it paid in 2019, i.e. parent sends the check on December 26th and the college posts it on January 2nd. That is the problem.
the reason the Box 1 expenses don't otherwise match is a number of expenses (room and board, books, etc) are not 'qualified expenses; however, TurboTax asks you for these non-qualified expenses in any event. to calculate credits available.
My advise is DO NOT override Box 1. You risk an audit. and if you do override Box 1 and end up with additional taxes and penalties, the Turbo Tax 'guarantee' will not cover you because you didn't post the 1098-T as it was documented.
p.s. the policy on pre-paid taxes isn't germane unless there is something in Pub 570 I've overlooked.
please advise if I have overlooked something or others think my logic is not sound.