Boulder County government offices are closed Monday, May 29, in observance of Memorial Day.

If you have questions about property valuation and property tax, visit

Special Mobile Machinery (SMM)

Appointments now required for in-person visits. Additionally, registration renewals need to be completed out of office. Options include online, by mail or drop box, or at a self-service kiosk. Read about these changes (including benefits, and FAQs). Información en español.

Registration of Special Mobile Machinery

Definition of Special Mobile Machinery (SMM):

  • Vehicles of a design commonly used in the construction business. These vehicles, self-propelled or otherwise, are not designed to transport persons or cargo over the public highways.
  • Motor vehicles which have been redesigned or modified with the attachment of special equipment or machinery (over 500 pounds), and this attachment becomes an essential part of the operation for which the vehicle was intended.

Registration Requirements

SMM equipment must be registered as soon as it goes to work in a for-hire capacity in the State of Colorado. If the SMM will be in Boulder County longer than 11 months, you must register it at one of our three MV branch locations.

In order to register and/or title heavy equipment or Special Mobile Machinery (SMM) in Boulder County, the following documentation is required:

  • Secure & Verifiable ID for the new owner
  • Bill of Sale
  • Equipment Invoice
  • Serial Number for the Unit (if not listed on the Bill of Sale or Equipment Invoice)
  • Affidavit of Ownership
  • Vehicle Title – must be properly endorsed by previous owner
  • Manufacturer’s Statement of Origin (MSO)

Out-of-state SMM equipment:

  • Most SMM equipment must be registered immediately upon entry to the State of Colorado.
  • Registration options for SMM equipment are available as SMM off-highway decals or on-highway plates.
  • If SMM is contacted at the Port of Entry and there is no proof of registration or taxation, it will be detained until proof is presented.
  • Please see the Colorado State Patrol website for more information on Port of Entry requirements.

Registration Exceptions

  • Specific Ownership Tax Permit (SOT)
    • A temporary permit that allows the SMM to work in Colorado for a minimum of 2 months but no longer than 11 months.
    • Can be obtained at any Port of Entry.
  • Ad Valorem Taxation (property tax exception)
    • For SMM operated solely on company property
    • Company may provide documentation that property taxes have been paid by presenting the Certificate of Ad Valorem Taxation

Contact Us

Motor Vehicle Division

**New as of Jan 4, 2021**
7:30 a.m. – 5:00 p.m. Mon-Thurs.
CLOSED Fridays
Online Contact Form
Contáctenos - Formulario en línea

Phone: 303-413-7710

Fax: 303-413-7725 (Boulder office)
Fax: 303-413-7002 (Lafayette office)
Fax: 303-678-6126 (Longmont office)


Boulder: 1750 33rd Street
Map & Directions

Longmont: 529 Coffman Street
Map & Directions

Lafayette: 1376 Miners Drive
Map & Directions

Mailing Address

1750 33rd Street, Suite 100
Boulder, CO 80301