Updated August 6, 2026 — registration steps, deadlines, and rates below were verified against official Massachusetts agency sources in August 2026. Confirm current figures with the agencies before filing.
Massachusetts employers register with two agencies: the Department of Revenue (income tax withholding, via MassTaxConnect) and the Department of Unemployment Assistance (UI, via Unemployment Services for Employers).
Unemployment liability triggers fast: one employee working at least one day a week for 13 weeks, or $1,500 in wages in any quarter; out-of-state employers hit it at just $200 of Massachusetts wages in a quarter.
Massachusetts also requires Paid Family and Medical Leave (PFML) contributions: 0.88% of eligible wages for 25+ covered individuals, 0.46% for smaller employers as of August 2026, remitted quarterly.
New hires and independent contractors must be reported to DOR within 14 days of the first day of work.
Withholding deposit frequency is set by projected annual withholding (annual, quarterly, monthly, or accelerated), and DUA wage reports are due by 3 p.m. on April 30, July 31, October 31, and January 31.
Watch for EMAC in year four: employers with six or more employees pay 0.12% to 0.34% on the first $15,000 of each employee's wages once the three-year exemption ends.
Why registration comes before your first paycheck
Massachusetts requires employers to withhold state personal income tax from every Massachusetts resident's wages and from nonresidents' wages for work performed in the state. That obligation begins with your very first payroll, so state registrations belong on the same checklist as your EIN and your first offer letter. Unemployment insurance liability arrives almost as quickly: you become subject once you have one or more employees working at least one day a week for 13 weeks in a calendar year (the weeks need not be consecutive) or once you pay $1,500 or more in wages in any quarter. If you are running payroll for the first time, plan to complete these registrations before your first pay date, because Massachusetts also expects new-hire reports within 14 days of an employee's start date.
The accounts a Massachusetts employer needs
Three programs, two agencies. First, a withholding tax account with the Massachusetts Department of Revenue (DOR), opened through its online portal, MassTaxConnect. Second, an unemployment insurance (UI) account with the Department of Unemployment Assistance (DUA), opened through the Unemployment Services for Employers portal. Third, Paid Family and Medical Leave (PFML): the Department of Family and Medical Leave (DFML) sets the rates, but employers withhold contributions from paychecks and remit them to DOR each quarter, so PFML rides on your DOR relationship rather than requiring a third standalone agency account. Employers in their fourth year and beyond may also owe the Employer Medical Assistance Contribution (EMAC), which DUA calculates from your quarterly wage filings.
Step-by-step registration
Get a federal EIN. Massachusetts requires businesses to register with an EIN, and DUA asks for it too.
Register with DOR on MassTaxConnect. Choose Sign Up, then Register a New Business. Have your EIN, business start date, legal and mailing addresses, and the titles and Social Security numbers of owners or officers. You will get a confirmation email, and you will set up two-step verification on first login. New businesses must file returns and pay withholding electronically regardless of size.
Register with DUA through the Unemployment Services for Employers homepage (do not log in first; select Register your Business). Per the DUA registration guide, you will need your legal business name, FEIN, entity type, state and date of incorporation, owner or officer Social Security numbers, and your principal Massachusetts business activity. Most registrations are processed immediately.
Set up PFML withholding in payroll. As of August 2026, employers with 25 or more covered individuals owe 0.88% of eligible wages (up to 0.18% for family leave and 0.28% for medical leave can be withheld from employees; the employer pays the remaining 0.42%). Employers with fewer than 25 covered individuals remit an effective 0.46% and owe no employer share. Rates are set annually; see the DFML contribution rate page. Note that a new law restructures the employer split starting January 1, 2027.
Collect Form W-4 and the Massachusetts Form M-4 from each employee, and report new hires within 14 days.
Once these accounts exist, most payroll software files these returns and deposits automatically.
Ongoing obligations
Withholding deposits follow projected annual withholding, as of August 2026: $100 or less files annually by January 31; $101 to $1,200 files quarterly by the last day of the month after each quarter; $1,201 to $25,000 pays monthly by the 15th of the following month (March, June, September, and December payments are due the last day of the following month); over $25,000 files quarterly but must pay over accelerated deposits within three business days whenever $500 or more has been withheld by the 7th, 15th, 22nd, or last day of a month. Returns go through MassTaxConnect (Form M-941), and employers also file quarterly wage reports and issue W-2s by January 31.
For UI, you file an employment and wage detail report and pay contributions by 3 p.m. on April 30, July 31, October 31, and January 31. New employers pay 2.42% in 2026 (6.08% for new construction employers) until DUA assigns an experience rate after three years; late payments accrue 12% interest. Two quirks to budget for: PFML contributions are due each quarter alongside this cadence, and EMAC begins in year four for employers with six or more employees in a quarter, at 0.12% of the first $15,000 of each employee's wages, rising to 0.24% in year five and 0.34% thereafter.
Remote and out-of-state employers
If you are a non-Massachusetts employer that conducts business or maintains an office in Massachusetts, you must withhold Massachusetts tax on wages for services performed there, reduced by any withholding for your home state. If your only connection to Massachusetts is a resident employee working outside the state, withholding is optional by mutual agreement, though the employee will still owe the tax. UI liability is stricter for out-of-state employers: contributions are required once you pay just $200 in gross Massachusetts wages in any quarter. Multistate employers may consolidate new-hire reporting with Massachusetts through MassTaxConnect if they register with the federal Office of Child Support Enforcement.
FAQ
When does a startup become liable for Massachusetts unemployment insurance?
You must contribute once you have one or more employees (permanent, temporary, or part-time) working at least one day a week for 13 weeks during the calendar year, or once you pay $1,500 or more in wages in any quarter. Registration is completed online through the Unemployment Services for Employers portal, and most registrations are processed immediately.
Do small startups have to deal with PFML?
Yes. Employers with fewer than 25 covered individuals still withhold and remit PFML contributions, at an effective 0.46% of eligible wages as of August 2026. The difference is that small employers owe no employer share of the medical leave contribution; they simply pass through what is withheld from employees, capped at the Social Security taxable maximum.
What is EMAC and should a new company worry about it?
The Employer Medical Assistance Contribution funds Massachusetts health insurance programs. New employers are exempt for their first three years of UI liability, and any employer with fewer than six employees in a quarter is exempt. After that it phases in at 0.12% (year four), 0.24% (year five), and 0.34% (year six onward) on the first $15,000 of each employee's annual wages. Good payroll software will track the phase-in automatically once your DUA account is connected.