Mont. Code Ann. § 37-45-204

The provisions of this chapter relating to the registration or licensing of a person, firm, or corporation, including the requirement of a bond with the state of Montana named as obligee and the collection of a fee, are exclusive for registered construction contractors. A political subdivision of the state may not require or issue any registrations, licenses, or bonds for the same or a similar purpose. However, this section does not limit or abridge the authority of a local government to levy and collect a general and nondiscriminatory license fee levied upon all businesses. This section does not limit the authority of a local government with respect to contractors not required to be registered under this chapter.