Over the years, I have had several clients come to me with issues regarding the retroactivity of a child support modification. These situations have included circumstances such as informal modifications of child support which were never filed with the court to demands from the other parent to make a modification retroactive to the date of a substantial change, such as a child turning 18 or graduating from high school, without any pending petition to modify. There is an easy answer, which often results in a difficult situation.

A child support order cannot be modified prior to the date that the party receives notice of the petition for modification. RSA 458-C:7 defines “notice” as either service as specified in the civil account or acceptance of a copy of the petition by certified mail receipt. The trial court may, however, order modification prospectively from the date of service forward. If it takes months, or even a year, to conduct a hearing and issue an order, either party runs the risk of the modification dating back to the time of service.

There is however a small narrow exception contained in the case law. In the case of In Re Nicholson the New Hampshire Supreme Court held that due to specific language in the parties divorce decree and uniform support order the child support could be modified retroactively to the time of the substantial change in circumstances (in this case a child becoming ineligible). In this case, the child support order had specific language as follows:

Unless the court … specifies differently, the amount of a child support obligation stated in the order for support shall remain as stated in the order until all dependent children for whom support is provided in the order shall terminate their high school education or reach the age of 18 years, whichever is later, or become married, or become a member of the armed forces, at which time the child support obligation terminates without further legal action. This amount shall remain as specified unless a legal order expressly allocates the payments on a per child basis.

This language is no longer in the standard uniform support order. Now, the SO -3C reads:

The effective date of any modification shall be no earlier than the date of notice to the other party. “Notice” means either of the following: 1) service as specified in civil actions or 2) the respondent’s acceptance of a copy of the petition, as long as the petition is filed no later than 30 days following the respondent’s acceptance.

Notwithstanding the narrow exception contained in Nicholson, it is very important that any agreements to modify child support be signed and filed with the court for approval. It is likewise critical that when a substantial change occurs, the petition must be filed immediately to preserve the ability to modify child support. Without taking these steps, a party could end up owing a substantial debt in child support when the other party seeks enforcement of the order rather than the informal agreement or the obligor has sat on their right to modify and must continue to pay at the higher rate of support.