Massachusetts

 

Last Updated June 17, 2026.

Massachusetts businesses must comply with withholding tax requirements, unemployment insurance obligations, and payroll reporting rules. Use these resources to connect with state agencies and employer services.

State Tax Guidelines

Massachusetts Department of Revenue – Withholding Tax

Agency Information

Add to existing company setup

Submit a request to your service team to add MA (withholding) to your company setup. Please include the below with your request:

  • Withholding – Withholding account number and Deposit Frequency.  If you’re unsure of your deposit frequency or account number you can call the agency at 617-887-6367.
  • Third Party Access – All clients are required to add permissions in order for us to file and pay taxes on your behalf.  Please review the Third Party Registration Instructions

Register a new company

Employers can register online at https://mtc.dor.state.ma.us/mtc/_/.  Under the Quick Links section select Register a new taxpayer.  Then select Register a business.  Follow the prompts to register your business.  Once completed you will receive your account number and deposit frequency.

Third Party Registration Instructions

  1. Go to: www.mass.gov/uima
  2. Scroll down and select Employer Login.  Login to your account – any issues contact (617) 626-5075 for assistance.
  3. Select Account Maintenance.
  4. Select Third Party Administrator (TPA) Authorization.
  5. Select New.
  6. Enter TPA ID provided to you from your service team.
  7. Enter Start dates.
  8. Check ONLY the boxes below for the following Roles:
    • Account Maintenance Update and Submit
    • Payments Update and Submit
    • Employment & Wage Detail Update and Submit
  9. Save.

Massachusetts Department of Unemployment Assistance – Unemployment tax

Agency Information

Add to existing company setup

Submit a request to your service team to add MASUI (unemployment) to your company setup. Please include the below with your request:

  • Unemployment – Account Number and Tax rate.  This can be found on a Tax Rate Notice or the Quarterly contribution report.  If you’re unsure of your tax rate or account number, you can call the agency at 617-626-5075.
  • Third Party Access – All clients are required to add permissions in order for us to file and pay taxes on your behalf.  Please review the Third Party Registration Instructions.

Register a new company

Register online at http://www.mass.gov/lwd/unemployment-insur/employers/.  Select Employer Login at the bottom of the page to begin.  Then select Employer Registration at the top left of the page.  Once completed you will receive your account number and rate.

Power of Attorney

Power of Attorney is required, please obtain the prefilled form from your client service representative.

  1. Go to: www.mass.gov/uima
  2. Scroll down and select Employer Login.  Login to your account – any issues contact (617) 626-5075 for assistance.
  3. Select Account Maintenance.
  4. Select Third Party Administrator (TPA) Authorization.
  5. Select New.
  6. Enter TPA ID provided to you from your service team.
  7. Enter Start dates.
  8. Check ONLY the boxes below for the following Roles:
    • Account Maintenance Update and Submit
    • Payments Update and Submit
    • Employment & Wage Detail Update and Submit
  9. Save.

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