NEW YORK (MainStreet) — Both banks and attorneys have been hesitant to provide services to state-compliant marijuana businesses for fear of violating federal laws.

"Large banks are afraid of running afoul of anti-money laundering charges in the future because they could be prosecuted by Attorney General Michael Huckabee," said David Downs, editor of the San Francisco Chronicle's pot blog Smell The Truth.

As a result, many dispensaries are run on a cash-only basis because of a lack of banks that will service them. That's because currently the plant-based drug remains classified as a Schedule 1 narcotic under the Federal Controlled Substances Act.

"Money that's stolen from a dispensary can't be traced right now, because it's all cash and weed," said Darrin C. Duber-Smith, marketing professor with Metropolitan State University of Denver. "So, I worry about the armed robbery of dispensaries, growers and suppliers. It's a risky proposition to deal with cash and marijuana has street value too."

The lack of banking services has led most dispensaries in California to offer clients an ATM inside. "There are reports of dispensary owners using safes to store cash and businesses that are misrepresenting themselves as florists or health food stores in order to open a bank account or secure a credit card," Downs told MainStreet.

Despite federal barriers, banks are slowly coming around. At a September 10, 2013 Senate Judiciary Committee hearing, the Justice Department's James Cole indicated that the government is in talks with bank regulators to determine whether financial institutions in states that have approved recreational marijuana use can do business with marijuana businesses; however, there is no timetable for formal guidelines.

"Marijuana is legal in some places and not others, so it's the agreement that people are accustomed to operating under that needs to be updated," said Rex Macey, senior vice president and chief investment officer with Wilmington Trust, the investment advisory arm of M&T Bank in Atlanta.

Although facilitators of the law, attorneys are not immune from the consequences of violating federal law.

"The riskiest legal services are those that require an attorney to take overt action action in furtherance of marijuana transactions that violates one of the eight enforcement priorities," said Jason Thompson, acting attorney with Washington-based GFarmaLabs, a cultivator, processor, wholesaler and distributor of medical and adult-use cannabis products.

The Department of Justice's eight enforcement priorities include preventing marijuana distribution to minors, preventing money from sales from going to criminal groups, preventing the diversion of marijuana from legal states to where the drug is still illegal and preventing criminal groups from using state laws as cover for trafficking of other illegal drugs.

"The safest legal services to provide is advice and counsel to a state-compliant marijuana business without taking any affirmative action on the business's behalf," Thompson told MainStreet. "An attorney must not cross the line by taking affirmative action that causes him or her to become complicit in violating federal law."

For now, both attorneys and banks will have to decide whether to serve marijuana businesses without the luxury of clear federal guidelines.

"It is getting easier, but banks and credit card companies need to catch up," Macey said.

—Written by Juliette Fairley for MainStreet