Doyle, Presiding Judge. In this discretionary appeal, Hector Perez, Jr., seeks review of a trial court order modifying his child support obligation. He contends that the trial court erred by retroactively modifying his child support obligation and by improperly applying an upward deviation based on his lack of parenting time without making sufficient factual findings. For the reasons that follow, we vacate the trial court’s order and remand with direction. The material facts are undisputed. Perez and Christina Cunningham are the unwed parents of one child who was born in June 2001. In June 2014, the trial court entered a consent order, awarding Cunningham sole legal and physical custody of the child. The court determined that Perez’s presumptive amount of child support was $492.47 per month, but because Cunningham owed Perez a child support arrearage of $7,632, the court awarded Perez a downward deviation in his support obligation. Accordingly, the court ordered Cunningham to pay Perez $212 per month for 36 months to pay off the arrearage and ordered Perez to pay Cunningham $280 per month until the child turned 18 years old, died, married, or otherwise became emancipated. Thereafter, on December 15, 2017, Cunningham filed a petition for modification of child support. In it, she apparently argued that Perez’s income had increased substantially and that he had failed to exercise any visitation with the child since June 2014. Following a bench trial, the trial court determined that Perez’s income was approximately $90,000 in 2017 and 2018, and he was living a comfortable lifestyle, including trips abroad. Cunningham has been unemployed since 2015, and the trial court imputed a minimum-wage income to her. The court also applied a parenting-time deviation in Cunningham’s favor in the amount of $300 because Perez had not exercised any visitation whatsoever. Based on these findings, the trial court modified Perez’s child support obligation to $1,267 per month, retroactive to the date of the modification petition. We granted Perez’s application for discretionary review. We review a trial court’s ruling on a petition to modify child support for abuse of discretion,[1] and we will uphold the factual findings underlying the ruling if they are supported by any evidence.[2] The trial court’s application of the law to the facts is reviewed de novo.[3] 1. Perez argues that the trial court erred by retroactively modifying his child support obligation. We agree. It is well-established that “[a] child support judgment [cannot] not be modified retroactively.”[4] Nevertheless, in its order entered on January 18, 2019, the trial court determined that Perez was responsible for paying the increased support obligation beginning January 1, 2018, the month after Cunningham filed her modification petition. Accordingly, the trial court ordered Perez to pay Cunningham an arrearage of $12,831 to account for the time before the order was entered. Thus, the trial court’s increase of Perez’s child support obligation retroactive to the date of Cunningham’s petition was contrary to law.[5] Accordingly, we vacate the trial court’s modification and remand for the court to enter a new order on a prospective basis from the date of the final order, January 18, 2019.[6] 2. Perez also argues that the trial court erred by applying a parenting-time deviation of $300 because Cunningham failed to present any evidence of additional child-rearing expenses due to her additional parenting time and that the court failed to make adequate findings of fact. We agree that the record appears unclear on this question, and we remand for entry of appropriate factual findings. A trial court is authorized to deviate “from the presumptive amount of child support when special circumstances make the presumptive amount of child support excessive or inadequate” due to, inter alia, “visitation rights not being utilized.”[7] Here, the trial court applied a parenting-time deviation in Cunningham’s favor in the amount of $300 because Perez did not exercise visitation for the four and one-half years leading up to the hearing. There was evidence to support this finding,[8] but in order to support such a deviation, the trial court: shall make written findings or special interrogatory findings that an amount of child support other than the amount calculated is reasonably necessary to provide for the needs of the child for whom child support is being determined and the order or special interrogatory shall state: (i) The reasons for the deviation from the presumptive amount of child support; (ii) The amount of child support that would have been required under this Code section if the presumptive amount of child support had not been rebutted; and (iii) How, in its determination: (I) Application of the presumptive amount of child support would be unjust or inappropriate; and (II) The best interest of the child for whom support is being determined will be served by deviation from the presumptive amount of child support.[9] In the instant case, the trial court determined that Perez’s presumptive amount of child support was $967.49. With regards to the parenting-time deviation, the trial court made no findings in the child support addendum or in its order. Similarly, in the child support worksheet docketed in January 2019 and incorporated into the final order, the court provided inadequate, single-word responses in the sections corresponding to the written findings required by OCGA § 19-6-15 (i) (1) (B).[10] Another worksheet from December 2017 appears in the record with more extensive findings, but it appears that the court did not incorporate the 2017 findings into its final order. In light of this conflicting record, and the explicit incorporation of inadequate written findings in the January 2019 worksheet, we vacate the $300 parenting-time deviation and remand for the court to enter appropriate factual findings, supported by the record, to support any deviation based on Perez’s failure to engage in visitation.[11] Any deviation shall be prospective from January 18, 2019. Judgment vacated and case remanded with direction. McFadden, C. J., and Hodges, J., concur.