Mobile Car Wash Permit Requirements in Billings, MT

1. EIN (Employer Identification Number)

   Required if you have employees or operate as an LLC or corporation. Free from the IRS, obtained instantly online.

   Official government source

   Free·Immediate (online application)

   Free

   Immediate (online application)

2. EPA Stormwater Compliance — Clean Water Act Section 402

   Mobile car wash operations that discharge wash water are subject to the federal Clean Water Act. The EPA's National Pollutant Discharge Elimination System (NPDES) prohibits discharge of polluted wash water to storm drains or waterways without a permit. Most mobile operators achieve compliance by using containment systems and disposing of water via sanitary sewer. Larger operations (e.g., fleet washing facilities) may require an NPDES permit.

   Official government source

   Free (containment equipment: $200–$1,500)·Before first wash

   Free (containment equipment: $200–$1,500)

   Before first wash

1. Montana Business Registration

   Mobile car wash and auto detailing businesses structured as an LLC, corporation, or partnership must register with the Montana Secretary of State (online via sosmt.gov). Sole proprietors operating under a business name file an assumed business name registration with the Secretary of State. An LLC is recommended to protect personal assets for mobile operations working on customers' property.

   Official government source

   $35 LLC Articles of Organization (online); $20 assumed business name·1–7 business days

   $35 LLC Articles of Organization (online); $20 assumed business name

   1–7 business days

2. Montana Environmental / Stormwater Compliance

   Mobile car wash operations generate wastewater containing detergents, surfactants, oils, and road grime. Montana environmental regulations — consistent with federal Clean Water Act requirements — prohibit discharge of this wash water to storm drains, street gutters, or waterways. Operators must use a wastewater containment mat and recovery system (wet/dry vacuum or pump), or must ensure wash water flows to a sanitary sewer inlet. Operators using hazardous cleaning solvents or degreasers may require a state permit. Contact the Montana Department of Environmental Quality for compliance guidance.

   Official government source

   Free–$200 (registration or permit fee, if required)·1–4 weeks (if permit required; otherwise immediate with self-compliance)

   Free–$200 (registration or permit fee, if required)

   1–4 weeks (if permit required; otherwise immediate with self-compliance)

1. Billings General Business License

   All mobile car wash and auto detailing businesses operating in Billings must obtain a general business license from the city. Mobile operations that travel to customers throughout the city are covered by a single city license. The application requires your business entity information, contact details, and a description of services. Renewed annually.

   Official government source

   Varies by business classification (annual business-license tax). The city does not publish its fee schedule online — contact City of Billings Finance, 406-657-8433, for current amounts.·1–2 weeks

   Varies by business classification (annual business-license tax). The city does not publish its fee schedule online — contact City of Billings Finance, 406-657-8433, for current amounts.

   1–2 weeks

2. Billings Stormwater / Wastewater Discharge Compliance

   Billings prohibits the discharge of mobile car wash wastewater into storm drains, gutters, or waterways. Wash water contains detergents, oils, and road grime that are harmful to local waterways. Operators must: (1) use a portable containment berm or mat to capture runoff, (2) vacuum up wash water with a wet/dry vac or pump, and (3) dispose of collected water at an approved sanitary sewer access point or licensed disposal facility. The city's Public Works or Stormwater division may conduct inspections. Violations may result in fines.

   $0 — Billings publishes no registration or inspection fee for mobile washing; the obligation is compliance with the city's stormwater (illicit discharge) rules: capture wash water and dispose to the sanitary sewer·1–3 weeks (self-certify compliance before operating)

   $0 — Billings publishes no registration or inspection fee for mobile washing; the obligation is compliance with the city's stormwater (illicit discharge) rules: capture wash water and dispose to the sanitary sewer

   1–3 weeks (self-certify compliance before operating)

3. Chemical handling: OSHA hazard communication and proper disposal (no county registration)

   Yellowstone County has no chemical-use registration for detailing businesses. Businesses using cleaning chemicals must follow OSHA hazard-communication requirements (Safety Data Sheets available to employees) and dispose of solvents and degreasers properly — never to storm drains. RiverStone Health's environmental programs do not license auto-detailing chemical use.

   $0 — no registration exists·1–2 weeks

   $0 — no registration exists

   1–2 weeks

4. Billings Home Occupation Permit (if operating from residence)

   A mobile car wash operator based at a Billings residence needs the standard city business license (home-based businesses are covered) and must comply with the zoning ordinance's home-occupation limits on traffic, signage, and outdoor storage. The city does not publish a separate home-occupation permit.

   Official government source

   No separate home-occupation fee published — covered by the city business license (annual business tax)·1–3 weeks

   No separate home-occupation fee published — covered by the city business license (annual business tax)

   1–3 weeks

Official Sources

• Billings Business Licensing
• Montana Environmental Quality — Water Programs
• EPA NPDES — Stormwater Discharges
• IRS EIN Application

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