Each US state has their own financial regulators and laws, and each approaches bitcoin differently. California and New York have been particularly aggressive in their pursuit of bitcoin-related organizations, for example, while others, such as New Mexico, South Carolina, and Montana, don’t regulate money transmitting businesses. A list of state approaches to money transmitter laws can be found here.

In May 2013, California’s state financial regulator issued a letter to the Bitcoin Foundation, a nonprofit organization designed to promote bitcoin, warning it that it may be a money transmission business, and threatening people there with potential fines and jail time.

Then, in August 2013, the New York Department of Financial Services issued subpoenas to 22 bitcoin-related companies, although these letters were more conciliatory, asking for a dialogue to develop appropriate regulatory guidelines for the digital currency industry. Since then, New York has acted more positively, with the state’s Superintendent of Financial Services, Benjamin M. Lawsky, announcing that it will accept applications for digital currency exchanges. Lawsky indicated that these businesses will be regulated under new New York regulation, which he committed to having in place by the end of the second quarter of 2014.

New York's BitLicense was the first virtual currency-specific licensing regime to address bitcoin and digital currencies in the US.

Developed by the New York State Department of Financial Services and released in June 2015, the regulation stands in contrast to decisions by US states such as Texas and Vermont to apply existing financial law to the use of the technology, as well as efforts in California to amend prior legislation.

It has emerged as the most recent example of the challenge governments face when attempting to regulate an emerging technology.