Tier Technologies Inc. of Reston, Va., said its Official Payments Corp. unit signed a contract to continue to provide electronic payments to the Internal Revenue Service for personal and business taxes.

Official Payments has handled tax payments since 1999. "We are delighted to continue this long-standing partnership," Ronald L. Rossetti, Tier's chairman and chief executive, said in a press release Tuesday. The new contract has a base period that began April 2 and four one-year option periods that run through 2013.

Official Payments and Metavante Technologies Inc. of Milwaukee are the only providers of online payments to the IRS.