In the post “Retroactive Support: What is it and how is the amount determined”, I wrote that the law defines retroactive support as support due for the time before a complaint or motion seeking support is filed, Briggs v. Greer, 136 NC App 294 (2000), and that the amount of retroactive support owed by an obligor can be determined based either on the Child Support Guidelines or on the parent’s share of actual expense incurred on behalf of the child during a period of time in the past. NC Child Support Guidelines, March 1, 2020, p. 2.