When changes are made to the total amount billed for the previous year, Box 4 is not populated when generating 1098T data.
According to the IRS...
Box 4. Adjustments made for a Prior Year
Payments Received. Enter reimbursements or refunds of qualified tuition and related expenses made during the calendar year that relate to payments received for any prior year after 2002.
Amounts Billed. Enter any reductions in charges made for qualified tuition and related expenses made during the calendar that relate to amounts billed that were reported for any prior year after 2002.
These requirements also apply to an adjustment made in connection with a nonresident alien for which the educational institution filed and furnished a Form 1098-T for the prior year.
For more information please see the IRS 1098T instructions at https://www.irs.gov/pub/irs-pdf/i1098et.pdf
We are currently evaluating this issue and will update this article when we have more information.
Steps to Duplicate
1. In Student Billing, Open a record for a current student 2.Create a credit that is marked to be included in qualified tuition and expenses and apply it to a charge from the previous year. This should reduce the amount billed. 3. Generate 1098T data for the current year for that student. 4. Note that Box 4 is still empty.