Oregon – Filing the Multnomah County Business Income Tax Return (MCBIT)

Article: 50445

Overview 

If you are subject to the Multnomah County Business Income Tax (MCBIT), you must complete and file a separate return. This return cannot be electronically filed through our software platform and must be printed and mailed to the Oregon Department of Revenue. 

Note: Refer to Knowledge Base Article 50032 for paper filing instructions. 

Print and Mail Only 

The Multnomah County Business Income Tax form must be filed by paper: 

  • It cannot be submitted electronically, even if you are e-filing your Oregon state
  • After completing the return, print and sign the form. 
  • Mail your completed form and any required to the address provided in the return instructions. 

Who Must File 

You are required to file a Multnomah County Business Tax return if: 

  • You operate a business within Multnomah County (including sole proprietorships, partnerships, LLCs, and corporations), 
  • Your business had gross receipts exceeding the exemption threshold (currently $50,000 for most filers), 
  • You conduct independent contractor work, or 
  • You are subject to the Portland Business License Tax and earned income within the county limits. 

Additional Resources 

Official forms and up-to-date filing instructions are maintained by the City of Portland Revenue Division, which administers both Portland and Multnomah County business taxes. 

You can find: 

  • Multnomah County Business Tax Return forms 
  • Payment vouchers 
  • Filing due dates 
  • Instructions for businesses and sole proprietors 

City of Portland Revenue Division – Business Taxes