Trevor Hughes

USA TODAY

SEATTLE – Hundreds of medical marijuana businesses here face closure because they're being told to get licenses that don't legally exist.

Marijuana dispensaries across Seattle began receiving letters last week telling them they need to get a special state license to remain open past next year. The problem? The state hasn't yet created those state licenses. Seattle has more than 330 medical marijuana businesses, which are less regulated than the city's handful of licensed recreational pot shops.

The city's letter is part of a larger effort to bring more regulation to the state's medical marijuana marketplace. Because the city doesn't specifically track which businesses are involved in the medical marijuana field, officials aren't sure how many actually face closure.

"Countless patients who rely on my services will have nowhere to go if my shop is shut down," Karl Keich, owner of Seattle Medical Marijuana Association, said in a statement. "I have paid more than $150,000 in taxes to the state of Washington and thousands more to the city of Seattle. Not only will this revenue stream be cut off if the city's plan is implemented, it will also put nine employees out of work."

While only Colorado and Washington state have legalized both recreational and medical marijuana, they went about it quite differently. Colorado allowed medical marijuana providers to also become recreational sellers, reasoning that they were already complying with the state's strict medical marijuana regulations. Washington's medical marijuana providers are far less regulated, and have been barred from simultaneously selling recreational marijuana.

Studies and police have identified medical marijuana stores as potential sources for black-market marijuana, and regulators in both states are considering clamping down on medical pot in order to force customers to buy from the more heavily taxed-and-regulated recreational stores.

In May, Seattle City Attorney Pete Holmes called on lawmakers to meld the state's recreational and medical marijuana systems. Holmes helped pass the ballot initiative legalizing recreational marijuana in Washington.

"Seattle's unregulated medical marijuana industry can help patients as a stopgap until (recreational stores) open, but we must ultimately fold medical marijuana producers and stores into a common statewide regulatory system," Holmes wrote in a news op-ed. "As a pioneer in ending marijuana prohibition, Washington has taken on the responsibility of showing the rest of the country — indeed, the world — that a legal and regulated marijuana market can succeed in reducing the harms of prohibitionist policies and promoting freedom, while maintaining public safety and public health.

Seattle officials say they aren't intending to shutter all the marijuana businesses, but note that city laws require the as-yet nonexistent state license. The letters sent this month say "major marijuana activity" businesses have until July 1, 2015, to get the license, get significantly smaller, or shut down.

"The city wanted to put that date far enough out so that the state legislature could consider a change in the regulatory process and ideally make some changes," said Bryan Stevens, a spokesman for Seattle's Department of Planning and Development. "The ideal solution would be some changes at the state level."

Washington's legislature reconvenes in January.