As @Bsch4477 said, 529 distributions are only qualified (tax-free) if they are taken in the same calendar year you paid for the qualified expense. So, you cannot take a distribution in 2025 to cover an expense you actually paid in 2024, even if the expense is associated with attendance in 2025.
Q. So, the question is can you use a 2024 529 distribution if you made a payment, in 2024, for an expense associated with attendance in 2025?
A. Yes, if the student was enrolled as a student in 2024, even if she did not actually take any classes.
"Qualified Higher Education Expenses (for a 529 Plan distribution)are expenses related to enrollment or attendance at an eligible postsecondary school. Some of the expenses must be required by the school and some must be incurred by students who are enrolled at least half-time, defined later. (Publication 970, page 50)".
Pub 970 makes the following statement regarding the tuition credits: "Generally, the credit is allowed for adjusted qualified education expenses paid in 2024 for an academic period beginning in 2024 or beginning in the first 3 months of 2025". You won't find the same wording regarding 529 distributions. But, you could assume the same rule applies.
