The U.S. IRS has published Program Manager Technical Advice 2018-016 addressing an overpayment of an installment of Section 965 Tax where there is still an overall Section 965 Tax due.  In this case, the PMTA reasons that when a taxpayer overpays an installment amount, it doesn't mean that the taxpayer has made an overpayment.

Code Section 965 provides for a one-time transition tax …