Sen. Cory Gardner (R-Colorado) on Monday introduced an amendment to a bill that would allow marijuana businesses to use bank accounts in states where pot is legal, according to a statement from the senator's office.

Gardner said he is confident the bill, which has wide bipartisan support, would be passed. 

Citing his motives to protect state's rights, Gardner's office announced on Friday the intention to "completely transform the way [cannabis companies] do business," according to a release from the senator's office. 

The amendment would exempt retailers from federal prosecution under the law - since marijuana is still a Schedule 1 drug at the federal level. Pot businesses would only be allowed to open bank accounts in states that have legalized marijuana. Pot will remain a Schedule 1 drug at the federal level even if this bill passes.

Sens. Gardner and Elizabeth Warren (D-Massachusetts) first proposed the STATES Act over the summer but it's seen very little traction. Its goal, according to Gardner's office, was to have federal marijuana regulations mirror state laws on pot. While allowing pot businesses access to banks is part of the bill, it's seen very little movement since it was introduced over the summer.

 According to Gardner's office, the senator decided to attach the STATES Act as an amendment to a popular criminal justice reform bill still working its way through Congress. Because of the amendment's relevance to the First Step Act, Gardner said he believes it will pass much easier in the Senate than on its own or attached to an unrelated bill.

Gardner admitted he hadn't talked to the president about the plan for the bill, but said the president supports the bill. 

This bill, if passed, would allow pot businesses to stop relying solely on cash. The owner of Peak Dispensary in Denver told 9NEWS there was "no downside to this."

"There's the transparency for the government that they're looking for while allowing us to continue to effectively operate our business," Justin Henderson said. "It's a convenience for our customers too. Right now, most of the smaller chains and the dispensaries were using cash and require customers to get cash out of an ATM."

This would allow some of the smaller pot shops to stop relying on cash and allow the use of cards to purchase marijuana.

Gardner said the use of banks would also help reduce the criminal element well-known in the marijuana industry prior to legalization.

"Advantages include public safety and more transparency and accountability," a Gardner spokesperson told Colorado Politics Monday. "The money would be able to be traced and accounted for instead of a purely cash business. That would help law enforcement ensure that the profits are going to legitimate, law-abiding investors rather than cartels. It would also help us better understand the size of the market and confirm that all taxes are being paid. In addition, it normalizes payroll for employees and allows Colorado workers in the industry to be treated the same as any other employee."

The federal government will no longer be able to prosecute companies that work with pot shops for money laundering if the bill is passed, the spokesperson added. 

According to the National Cannabis Industry Association, 10 states have legalized recreational marijuana and 21 allow medical marijuana sales. The First Step Act would affect all of them.