San Mateo, Calif. - Bitpass, a four-year-old, San Mateo-based provider of online payment processing services, said that it is discontinuing operations due to "circumstances beyond our control," CEO Matthew Graves wrote in an email to customers. The company said that it will close all of its U.S. Buyer accounts on Jan. 26, refunding all unspent monies to account holders. Bitpass said that the changes do not affect buyers and merchants with Australian dollar denominated accounts. The company has raised a total of $13 million in venture capital financing during its course of operations.