How to collect unpaid child support in Missouri

The agency's collection tools, what federal law adds, and a ready letter to ask for enforcement.

Checked against official sources: Oct 25, 2026.

Short answer

Arrears means child support that is past due. Past-due child support on Missouri orders entered on or after September 1, 1982 draws simple interest of 1% per month (12% a year).

Interest on unpaid support
12% a year
License suspension
Arrears equal to or more than three months of support or $2,500, whichever is less, as of the date the notice of intent to suspend is served; or failing to obey a subpoena or a genetic testing order.
Passport denial
Over $2,500 past due (federal law)

What the agency can do in Missouri

Arrears means support that is past due. The child support agency can use these tools to collect it:

  • Income withholding
  • Driver's, professional, occupational, hunting and fishing license suspension
  • Tax refund offset
  • Liens
  • Credit bureau reporting
  • Court contempt

Law: RSMo §454.1003

Ask the agency in writing to collect what is owed: Ask the agency to collect unpaid support

Interest on arrears in Missouri

Past-due child support on Missouri orders entered on or after September 1, 1982 draws simple interest of 1% per month (12% a year). It accrues automatically, but no payment counts as interest until all the unpaid support is paid. To collect interest by execution, the parent owed support must file a sworn affidavit of payment history with the circuit clerk.

Law: RSMo §454.520

When a license can be suspended in Missouri

Arrears equal to or more than three months of support or $2,500, whichever is less, as of the date the notice of intent to suspend is served; or failing to obey a subpoena or a genetic testing order. Business, professional and occupational licenses can only be suspended by a court.

Law: RSMo §454.1003

What federal law adds

  • Tax refunds. The federal government can take a federal tax refund to pay past-due child support. Law: 42 U.S.C. 664
  • Passports. A parent who owes more than $2,500 in past-due support can be refused a passport. Law: 42 U.S.C. 652(k)
  • Pay withholding limit. For support, up to 50% of take-home pay can be withheld if the parent supports another spouse or child, or 60% if not. It is 55% or 65% when support is more than 12 weeks behind. Law: 15 U.S.C. 1673(b)
  • Past-due support. Each unpaid payment becomes a judgment on the day it is due. It can't be lowered later, except back to the date the other parent got notice of a request to change the order. Law: 42 U.S.C. 666(a)(9)

In nearby states

What to do now in Missouri

  1. Track what was paid

    Note the date and amount of each payment, and each missed one.

  2. Open a case or ask the agency

    Contact Missouri Department of Social Services, Family Support Division (FSD), Child Support Program (866-313-9960) · Apply online

  3. Share what you know

    Tell the agency where the other parent works or lives.

  4. Get the numbers in writing

    Ask the agency for the total owed, with any interest.

Free help in Missouri

Questions about unpaid support in Missouri

What can the agency do about unpaid support in Missouri?

Arrears means support that is past due. The child support agency can use these tools to collect it: Income withholding; Driver's, professional, occupational, hunting and fishing license suspension; Tax refund offset; Liens; Credit bureau reporting; Court contempt.

Can unpaid support cost a driver's license in Missouri?

Arrears equal to or more than three months of support or $2,500, whichever is less, as of the date the notice of intent to suspend is served; or failing to obey a subpoena or a genetic testing order. Business, professional and occupational licenses can only be suspended by a court.

Is there interest on unpaid child support in Missouri?

Past-due child support on Missouri orders entered on or after September 1, 1982 draws simple interest of 1% per month (12% a year). It accrues automatically, but no payment counts as interest until all the unpaid support is paid. To collect interest by execution, the parent owed support must file a sworn affidavit of payment history with the circuit clerk.

More for Missouri

Sources

Sources

Last checked: Oct 25, 2026.

Federal sources