Interest on child support arrears accrues automatically in most states the moment a payment is missed, at a statutory rate that can run anywhere from about 4 percent to 12 percent per year, and the resulting debt is legally enforceable on top of the unpaid principal. Federal law treats each missed installment as a judgment the day it comes due, so neither the original amount nor the interest can be erased retroactively.1Office of the Law Revision Counsel. 42 USC 666 – Requirement of Statutorily Prescribed Procedures to Improve Effectiveness of Child Support Enforcement Interest can still be reduced or waived in specific situations: through a state arrears compromise program, a court order based on hardship or accounting error, or a judge-approved agreement with the other parent.
How Interest Accrues
Interest typically begins running shortly after a payment’s due date. Some states start the clock the day the payment was missed; others wait until the end of the month. Once it starts, it runs continuously until the balance is paid or a court modifies the obligation.
Most states apply simple interest, calculated only on the unpaid principal. Arizona, Oregon, Texas, and West Virginia all limit charges to simple interest. A few states allow compounding. Colorado, for example, applies compound interest on child support arrears. The difference adds up: on a $10,000 balance at 10 percent, simple interest adds $1,000 a year, while compound interest adds progressively more each year as prior interest generates its own charges.
Rates vary widely. Roughly a dozen states charge 10 percent or more annually, while others sit as low as 4 percent. Several tie their rate to a fluctuating benchmark like the prime rate, and a handful leave the figure to the court’s discretion. Interest continues to accrue even after the child turns eighteen, because the debt is a judgment against the parent and does not expire when the child reaches adulthood.
Why the Principal Can’t Be Reduced but Interest Sometimes Can
The federal Bradley Amendment bars any court or parent from retroactively reducing child support that was already due.1Office of the Law Revision Counsel. 42 USC 666 – Requirement of Statutorily Prescribed Procedures to Improve Effectiveness of Child Support Enforcement Each installment became a judgment the day it came due, and that judgment stands. Accumulated interest, by contrast, has more room to move. State programs, courts, and private settlements can all touch interest in ways they cannot touch principal, which is why most relief efforts focus there.
When Arrears Trigger Federal Enforcement
Several federal collection tools kick in at specific dollar thresholds, and accumulated interest counts toward the arrears total. Letting interest pile up can push a case into enforcement territory the parent could have avoided.
- Passport denial once arrears exceed $2,500. The state certifies the case to the federal government, which directs the State Department to refuse, revoke, or restrict the passport. Dropping below $2,500 after certification does not automatically restore eligibility.2Office of the Law Revision Counsel. 42 USC 652 – Duties of Secretary
- Federal tax refund interception when arrears reach $500 or more.3Office of the Law Revision Counsel. 42 USC 664 – Collection of Past-Due Support From Federal Tax Refunds
- Suspension of driver’s, professional, and recreational licenses. Every state must have procedures for this.1Office of the Law Revision Counsel. 42 USC 666 – Requirement of Statutorily Prescribed Procedures to Improve Effectiveness of Child Support Enforcement
- Credit bureau reporting of delinquent parents, after notice and a chance to dispute.1Office of the Law Revision Counsel. 42 USC 666 – Requirement of Statutorily Prescribed Procedures to Improve Effectiveness of Child Support Enforcement
A parent who owes $15,000 in principal may owe $22,000 or more once interest is added, and the higher total is the number the enforcement thresholds look at.
Which State’s Interest Rate Applies If Parents Live Apart
When parents live in different states, the Uniform Interstate Family Support Act, adopted by every state, controls. The law of the state that issued the original order governs how interest accrues.4Administration for Children and Families. Action Transmittal: Interstate Child Support Policy Registering the order in a new state for enforcement does not change the rate.
The rate can change if a court in the new state formally modifies the order. The modified order then becomes the controlling order, and the new state’s interest laws apply going forward to future arrears and to any consolidated balance from the original order.5Administration for Children and Families. 2001 Revisions to Uniform Interstate Family Support Act A move alone changes nothing; a modification can change a great deal.
Bankruptcy Will Not Erase It
Filing for bankruptcy does not discharge child support or the interest on it. Federal bankruptcy law defines child support as a domestic support obligation and specifically includes “interest that accrues on that debt as provided under applicable nonbankruptcy law.”6Office of the Law Revision Counsel. 11 USC 101 – Definitions Neither Chapter 7 nor Chapter 13 can wipe it out.7Office of the Law Revision Counsel. 11 USC 523 – Exceptions to Discharge Child support also takes first priority among unsecured claims, ahead of credit cards and medical bills.8Office of the Law Revision Counsel. 11 USC 507 – Priorities In a Chapter 13 plan, every dollar of child support arrears, interest included, must be paid in full over the life of the plan.
State Arrears Compromise Programs
About 45 states and the District of Columbia run some form of arrears compromise program. The specifics vary, but most target debt owed to the government rather than to the custodial parent. That government-owed portion generally arose because the custodial parent received public benefits like cash assistance or foster care, and the noncustodial parent was required to reimburse those costs.
Most programs let a parent pay a reduced lump sum, or commit to consistent monthly payments, in exchange for a reduction of the balance including accumulated interest. Eligibility typically depends on income, assets, family size, and cost of living. Some programs require the parent to show the total debt exceeds what could reasonably be paid over a set number of years. Others forgive a portion of arrears for each consecutive on-time payment.
These programs run through the state child support agency, not the court. A parent applies directly, provides financial documentation, and receives a determination. Completing the program’s requirements permanently removes the forgiven amount from the ledger. The limitation: these programs almost never reduce debt owed to the other parent. That part requires either a court order or a private agreement.
Court-Ordered Interest Waivers
Judges can reduce or waive interest, but they need a legal reason. The grounds courts generally consider fall into a few categories.
Accounting errors are the cleanest basis. If the agency miscalculated interest, failed to credit payments, or applied payments to the wrong case, the court can correct the ledger. There’s no policy judgment, just a fix.
Undue hardship is a common ground where state law allows it. Courts look at whether the parent has income or assets to pay, whether paying the interest would undermine current support, and whether serious illness or disability contributed to the original nonpayment.
Good cause for the original nonpayment matters in some states. Incarceration, military deployment, or a documented medical crisis is a stronger argument than a choice not to pay.
Prejudice from delayed enforcement sometimes works when the custodial parent waited many years to pursue collection, allowing interest to balloon far beyond what timely action would have produced. This argument is harder to win and tends to succeed only when the delay looks strategic.
Any of these requires a formal motion, a hearing, and evidence. A verbal request or a letter will not do. If the judge grants relief, a written order goes to the agency, which updates its records to match.
Private Agreements Between Parents
A custodial parent can agree to waive some or all of the interest, often in exchange for a lump-sum payment of the principal. For the agreement to hold, it must be in writing and approved by a judge. An informal promise, even a signed letter or text between the parents, will not stop the child support agency from continuing to track and collect the interest. The agency follows the court order on file. Once a judge signs a stipulation reflecting the deal, the agency updates the balance. Parents who skip the court approval step often find years later that the forgiven interest is still on the books.
Preparing and Filing a Waiver Request
The starting point is a certified payment history from the local child support agency.9Administration for Children and Families. How Can I Access Payment Information on My Child Support Account It shows every payment received, the dates applied, and the running principal and interest balances. That document is the foundation for spotting missed credits or miscalculated interest. If the history looks wrong, a written request to the agency for a formal audit, with the case number and the time period in question, is the next step. If the agency won’t cooperate, a motion for a formal accounting can be filed with the family court.
Beyond the payment history, a financial disclosure, sometimes called an income and expense declaration, lists income and monthly expenses. This is where the hardship argument lives. Supporting documents matter: medical records showing disability or serious illness, unemployment statements, proof of other dependents, and anything else explaining why the full balance cannot be paid. The showing is that the debt exceeds realistic ability to pay, not just that payment would be inconvenient.
The motion and supporting documents are filed with the clerk of the court that issued the original child support order. Filing fees vary, and low-income parents can usually request a fee waiver. Copies must be formally served on the other parent and the state child support enforcement agency, with proof of service filed before the hearing. The hearing is typically scheduled within a few weeks to a couple of months. The parent presents the financial evidence; the other parent and the agency can respond. If the judge grants the request, a written order goes to the agency and the account balance is adjusted. If denied, a parent can sometimes refile later when circumstances change significantly, but repeating the same motion without new facts will not be received well.