The division of child support (DCS) serves a notice and finding of financial responsibility (NFFR), notice and finding of parental responsibility (NFPR), or notice and finding of medical responsibility (NFMR) in the following manner:

(1) On the noncustodial parent:

(a) By certified mail, return receipt requested; or

(b) By personal service.

(2) On the custodial parent:

(a) By first class mail to the last known address, if the custodial parent is the one who applied for services.

(b) In the same manner as on the noncustodial parent, if the custodial parent is not the one who applied for services.