Currently, Washington is not accepting any applications for marijuana business licenses, but may reopen the application process soon. Licensing is ran by the Liquor and Cannabis board in Washington. Washington has very specific licenses, depending on which part of the marijuana business you are partaking in. Requirements for each license vary greatly when they are accepting applications.
If you want to try and open a dispensary in Washington state and you will need to contact the federal government and apply for this privilege. You can search online to find the appropriate parties to apply for and fill out all of the proper paperwork and hope that they will accept you.
If you plan in doing marijuana business in Washington, you need a license from the State Liquor and Cannabis Board. Unfortunately they are not accepting applications at this time. There are different licenses for different types of businesses, however, and most of the information is available at http://www.liq.wa.gov. There you can preview the paperwork, fees and other requirements you’ll need.