23 Pa C.S. Section 4321 provides that married persons are liable for the support of their spouse according to their respective abilities to provide and parents are liable for the support of their unemancipated children under 18 years of age. Domestic Relations is the branch of the court that handles support applications. An application for support can be filed with their office in the county where you reside or where the payor resides. An application can also be initiated online through the support program website. Support between spouses is based on the difference in income. 40% of the difference in income can be awarded in a case where there are no children. 30% of the difference in income is appropriate where there is also a child support component. Child support in Pennsylvania is based on statewide guidelines established by the Pennsylvania Supreme Court. The guidelines are based on an "Income Shares Model" such that the guideline amount is shared by the parties based on percentage of custody time as well as percentage of income.