(dissenting in part and concurring in part):
I would reverse the family court’s recalculation of child support utilizing Worksheet C in place of the originally agreed upon Worksheet A of the South Carolina Child Support Guidelines (the Guidelines), and for that reason, I respectfully *256dissent. I adopt the majority’s facts and standard of review, but I disagree with the analysis and would find as follows.
The majority utilizes Upchurch v. Upchurch for the proposition that the family court may always modify child support upon a proper showing of change in either the child’s needs or the supporting parent’s financial ability. 367 S.C. 16, 26, 624 S.E.2d 643, 647-48 (2006). While I agree with the majority that due to significant changes in the parties’ income, a modification of the child support amount was appropriate, I find this modification should have been calculated under Worksheet A of the Guidelines.
In an August 30, 2000 order (the 2000 order), the family court fully approved, incorporated and merged the parties’ custody, support and property settlement agreement into its order. This agreement called for Mother to pay “Father the amount of $920.00 per month in child support based upon figures set forth in the attached Child Support Obligation Worksheet A.” The family court found that the parties had negotiated and entered into the agreement with “the benefit of advice and counsel” and that they “fully comprehended its terms and conditions.” Further, the court found each party entered into a “fair, equitable, and reasonable” agreement “freely, knowingly, voluntarily, and without threats or coercion.”
I first note that this 2000 order of the family court was never appealed. Therefore, it has become the law of the case, and any review of the propriety of utilizing Worksheet A, as noted in the parties’ agreement and consequently the court’s order, would be contrary to our rules of preservation.4 The majority correctly notes regulation 114-4730(A) of the South Carolina Code (Supp.2006) provides a family court with discretion to apply a “shared custody adjustment” which provides for the utilization of Worksheet C to calculate child support for parents who have court ordered visitation with a *257child for more than 109 overnights each year. However, to review the family court’s 2000 order for an abuse of discretion error at this juncture would be inappropriate. The proper query to be addressed in this matter is whether the necessary change of circumstances has occurred to modify the original order by calculating child support under Worksheet C instead of Worksheet A. Nonetheless, even were we to review the propriety of utilizing Worksheet A in the 2000 order, I believe this issue fails on its merits. The majority notes that the family court failed to provide specific findings of fact to explain why it deviated from the Guidelines in calculating the child support owed. While I agree that were the court to deviate from the Guidelines in its own discretion it would have to provide specific findings to justify this action, in this matter, the parties agreed to utilize Worksheet A. The parties are free to agree on child support which is greater than that as required by law. See Ratchford v. Ratchford, 295 S.C. 297, 299, 368 S.E.2d 214, 215 (Ct.App.1988) (“A parent can contractually obligate himself beyond the support requirements imposed by law.”). Where the parties agree to a greater amount of support than required by law, I fail to discern why the family court should be required to make specific findings of fact to justify such deviation from the Guidelines.5
Regardless of the propriety of the family court’s application of Worksheet A to calculate child support under the 2000 order, as noted above, the family court retains jurisdiction to modify child support upon a proper showing of change in either the child’s needs or the supporting parent’s financial ability. “Where there is an agreement regarding child support, however, the family court should not decide support issues as if there is no agreement.” Ratchford, 295 S.C. at 299, 368 S.E.2d at 215. The parties agreed to calculate the support obligation under Worksheet A, and as reflected in the 2000 order, this calculation based on the parties then existing *258income, resulted in an amount of $920.00. While the dollar amount was determined through a calculation based on the parties’ then existing incomes and not based on the parties’ specific assent, the decision to utilize Worksheet A was agreed upon by the parties. Consequently, I believe that while the dollar amount is modifiable based on changes in the income of the parties, I do not find the use of Worksheet A to be modifiable baséd solely on changes in the parties income.6’ A change in worksheets should be predicated on a change in the visitation such that Mother would increase her overnights from an amount less than 109 nights to an amount in excess of 109 nights thereby providing the court with discretion to apply the shared custody adjustment as noted in regulation 114-4730(A) of the South Carolina Code (Supp.2006). However, it is undisputed that Mother was afforded visitation in excess of 109 overnights in the 2000 order. Consequently, she agreed to calculate her support obligation under Worksheet A while already having visitation in excess of 109 overnights per year. Mother “freely, knowingly, voluntarily, and without threats or coercion” agreed to forego the possibility of a shared custody adjustment. Therefore, we have no substantial change in the visitation, and Mother is not entitled to a modification of her previously agreed to usage of Worksheet A.
Further, the majority cites Upchurch for the notion that “changes within the contemplation of the parties at the time of the initial decree are not sufficient bases for the modification of a child support award.” 367 S.C. at 26, 624 S.E.2d at 648. I agree and can discern no manner in which one could argue Mother, having been afforded over 109 overnights per year by the 2000 order and thereby potentially being entitled to a shared custody adjustment, did not have the use of a particu*259lar worksheet within her contemplation when she agreed to utilize Worksheet A.
For these reasons, I would reverse the family court’s usage of Worksheet C and remand the issue of child support for calculation of a proper support obligation under the agreed upon Worksheet A. As to the other issues noted in this appeal, I concur with the majority.
. We are mindful that the appellate courts of this state have disregarded rules of error preservation where the best interests of a child were concerned. See Joiner v. Rivas, 342 S.C. 102, 107, 536 S.E.2d 372, 374 (2000). However, as the majority notes, the changing of worksheets in this matter does not effect the interests of the children; "it was simply a mathematical calculation on the part of the trial court to establish support based on the guidelines.”
. The North Carolina Court of Appeals case (Beamer v. Beamer, 169 N.C.App. 594, 610 S.E.2d 220 (2005)), utilized by the majority to support its point that deviation from the Guidelines must be supported by specific findings of fact, is distinguishable from the matter at hand. In the Beamer case, there was no agreement by the parties as to which worksheet to apply, and the court sua sponte determined it should calculate support in a manner not consistent with the North Carolina Guidelines.
. I again note the majority’s use of Beamer to establish that “once a substantial change in circumstances has been shown by the party seeking modification, the trial court then ‘proceeds to follow the Guidelines and to compute the appropriate amount of child support.' ’’ This intimates that once a substantial change has been found, the court is free to change even the worksheet to be used. This may hold true in cases such as Beamer where there is no prior agreement of the parties as to which worksheet to use. However, in light of the precedent handed down in Ratchford dictating that where there is an agreement, the court should not decide support issues as if there is no agreement, I find Beamer to be unpersuasive under the facts of this case.