OTR’s Customer Service Administration District of Columbia Customer Service Center Customer Service Center contact the D.C. Office of Tax and Revenue contact the D.C. Office of Tax and Revenue contact the DC Office of Tax and Revenue http://otr.cfo.dc.gov/service/customer-service-center otr.cfo.dc.gov/service/customer-service-center contact the D.C. Office of Tax and Revenue District of Columbia contact the D.C. Office of Tax and Revenue DC Office of Tax and Revenue contact the D.C. Office of Tax and Revenue contact the D.C. Office of Tax and Revenue contact the D.C. Office of Tax and Revenue contact the D.C. Office of Tax and Revenue contact the D.C. Office of Tax and Revenue contact the D.C. Office of Tax and Revenue Customer Service Center