Pennsylvania law requires withholding at a rate of 3.07 percent on non-wage Pennsylvania source income payments made to nonresidents. Who is require to withhold?• Withholding Agent. Employers are only required to withhold the LST on a payroll period basis for those payroll periods in which the taxpayer is employed. We embrace our responsibility as independent auditors to perform highquality audits that promote trust and confidence in the capital markets.