This must be filled out and submitted no later than 3 p.m. On the business day before the scheduled payment due date.Our mailing address is 160 East 300 South, P.O. Box 146705, Salt Lake City UT, 84114-6705. You can make your loan payment online. Salt Lake County accepts three forms of payment for paying online: e-Check - Electronic check drawn against a checking account. You may search and pay for Traffic and Criminal cases. You will need your court case number, citation number, or driver's license number to find your case. Salt Lake City will be sending out information with renewal notices. You get an automatic extension of up to six months to file your return. You do not need to file an extension form, but we will assess penalties.