FL-421 is a California family court attachment form used in governmental child support cases, typically those handled by the Local Child Support Agency (LCSA), to provide a detailed breakdown of child support payments connected to a Declaration of Payment History (FL-420). When the payment history is too long or complex to fit on FL-420 alone, FL-421 is used to list additional payments, adjustments, credits, arrears, and interest. This attachment ensures the court receives a complete and accurate record of the financial history of the support order.

The form includes line-by-line entries for every payment received, including wage garnishments, direct payments, tax refund intercepts, unemployment deductions, disability benefit intercepts, and any other sources. It shows the date of payment, the amount, and how the payment was applied—whether toward current support, past-due support (arrears), interest, or fees. Because LCSA cases often involve long histories of payments and adjustments, FL-421 provides the expanded space needed to document everything clearly.

FL-421 plays a critical role when the court must determine accurate arrears balances, verify disputed payments, or ensure that all credits were properly applied. Parents sometimes claim payments were made directly to the other parent or dispute how the agency allocated previous payments. FL-421 helps resolve these issues by presenting a clear, official, itemized record that the court can rely on. This transparency helps prevent errors and ensures support obligations are tracked correctly.

The attachment is used in hearings related to arrears judgments, support modifications, contempt proceedings, enforcement actions, and audits requested by either parent or the agency. Courts often require FL-421 when the support history spans many years or when multiple employers, payment sources, or enforcement tools have been involved. It ensures that the judge has a complete financial picture before making decisions about owed support or payment plans.

In summary, FL-421 is an essential extension of the payment history provided in governmental parentage and support cases. It offers the detailed, itemized records necessary for the court to evaluate child support payments, determine accurate arrears, and ensure proper enforcement. When paired with FL-420, FL-421 provides a reliable financial record that supports fair and accurate child support rulings.