(750 ILCS 28/40)
    Sec. 40. Petitions to contest withholding or to modify, suspend, terminate, or correct income withholding notices.
    (a) When an obligor files a petition to contest withholding, the court, after due notice to all parties, shall hear the matter as soon as practicable and shall enter an order granting or denying relief, ordering service of an amended income withholding notice, where applicable, or otherwise resolving the matter.
    The court shall deny the obligor's petition if the court finds that when the income withholding notice was mailed, sent by facsimile transmission or other electronic means, or placed for personal delivery to or service on the payor:
        (1) a delinquency existed; or
        (2) the parties' written agreement providing an
    
alternative arrangement to immediate withholding under subsection (a) of Section 20 no longer ensured payment of support.
    (b) At any time, an obligor, obligee, public office or Clerk of the Circuit Court may petition the court to:
        (1) modify, suspend or terminate the income
    
withholding notice because of a modification, suspension or termination of the underlying order for support; or
        (2) modify the amount of income to be withheld to
    
reflect payment in full or in part of the delinquency or arrearage by income withholding or otherwise; or
        (3) suspend the income withholding notice because of
    
inability to deliver income withheld to the obligee due to the obligee's failure to provide a mailing address or other means of delivery.
    (c) At any time an obligor may petition the court to correct a term contained in an income withholding notice to conform to that stated in the underlying order for support for:
        (1) the amount of current support;
        (2) the amount of the arrearage;
        (3) the periodic amount for payment of the arrearage;
    
or
        (4) the periodic amount for payment of the
    
delinquency.
    (d) The obligor, obligee or public office shall serve on the payor, in the manner provided for service of income withholding notices in subsection (g) of Section 20, a copy of any order entered pursuant to this Section that affects the duties of the payor.
    (e) At any time, a public office or Clerk of the Circuit Court may serve a notice on the payor to:
        (1) cease withholding of income for payment of
    
current support for a child when the support obligation for that child has automatically ceased under the order for support through emancipation or otherwise; or
        (2) cease withholding of income for payment of
    
delinquency or arrearage when the delinquency or arrearage has been paid in full.
    (f) The notice provided for under subsection (e) of this Section shall be served on the payor in the manner provided for service of income withholding notices in subsection (g) of Section 20, and a copy shall be provided to the obligor and the obligee.
    (g) The income withholding notice shall continue to be binding upon the payor until service of an amended income withholding notice or any order of the court or notice entered or provided for under this Section.
(Source: P.A. 90-673, eff. 1-1-99.)