When Are Massachusetts Taxes Due and What Happens If You Miss the Deadline?

Tax deadlines can be easy to overlook, but missing them can result in penalties and added costs. Massachusetts has its own tax filing rules, separate from federal requirements, that residents and businesses must follow. Understanding these deadlines helps avoid unnecessary fees and complications.

Standard Filing Deadline

Massachusetts tax returns for individuals follow the federal timeline, with a due date of April 15. If this falls on a weekend or holiday, the deadline moves to the next business day. In 2025, April 15 falls on a Tuesday.

State tax obligations apply to full-year residents, part-year residents, and nonresidents earning income in Massachusetts. Individuals must file a return if their gross income is at least $8,000, a lower threshold than the federal requirement. Some taxpayers who don’t need to file federally may still have to file with the state.

Massachusetts has a flat income tax rate of 5% for most taxable income as of 2024. An additional 4% surtax applies to annual income over $1 million under the Fair Share Amendment. High earners must include this surtax in estimated payments and final tax liabilities.

Extensions

Massachusetts grants an automatic six-month extension to file individual income tax returns, moving the deadline to October 15. No formal request is required, but this extension applies only to filing, not to paying taxes owed. Any balance must be paid by April 15 to avoid interest and penalties.

Taxpayers can estimate their owed amount using Massachusetts Form M-4868, though filing the form is not required. The extension remains valid if at least 80% of the total tax liability is paid by April 15 through withholding, estimated payments, or direct payments. Falling short of this threshold can result in late payment penalties.

Businesses must actively apply for an extension using Form 355-7004 or Form 63-29A, depending on their entity type. Corporations generally receive six-month extensions, while certain trusts and estates qualify for five and a half months. As with individuals, businesses must pay any expected tax liability by the original due date to avoid penalties.

Estimated Payment Obligations

Taxpayers expecting to owe more than $400 after withholding and credits must make estimated tax payments throughout the year. This primarily affects self-employed individuals, independent contractors, investors with significant capital gains, and high-income earners subject to the surtax.

Estimated taxes are due in four equal installments on April 15, June 15, September 15, and January 15 of the following year. If a due date falls on a weekend or holiday, the deadline moves to the next business day. Late or insufficient payments can result in interest charges, calculated using the state’s underpayment rate, which is adjusted quarterly.

Taxpayers can calculate estimated payments using either the prior-year safe harbor method or the current-year liability method. The safe harbor rule allows individuals to avoid penalties by paying at least 100% of the previous year’s tax liability, or 110% if their adjusted gross income exceeded $150,000. The current-year method requires payments to cover at least 90% of the final tax owed. Choosing the right approach depends on income stability and expected earnings changes.

Penalties and Interest

Missing Massachusetts tax deadlines can lead to financial penalties. The state imposes a late filing penalty of 1% of the unpaid tax per month, up to 25%. If a return is filed more than 30 days after a formal demand from the Department of Revenue (DOR), an additional penalty of $100 or 10% of the unpaid tax—whichever is greater—may apply.

Interest on unpaid taxes is based on the federal short-term rate plus four percentage points, compounded daily. This rate is adjusted quarterly. Even taxpayers who file on time but underpay may face interest charges.

A negligence penalty of 20% applies if the DOR determines a taxpayer has significantly understated their liability due to careless or reckless disregard of tax laws. More serious cases, such as willful tax evasion, can result in criminal penalties, including fines and imprisonment.

Payment Arrangements

For taxpayers unable to pay their full balance by the due date, Massachusetts offers structured payment plans to help individuals and businesses manage their obligations while minimizing penalties and interest.

Short-term payment plans are available for balances under $5,000 and typically last up to six months. These can be set up online through MassTaxConnect without requiring financial disclosures. For debts exceeding $5,000, longer-term agreements may be possible, but the DOR may request proof of financial hardship, such as bank statements or income documentation. While an installment plan prevents enforcement actions, interest continues to accrue until the balance is paid.

If a taxpayer defaults on an agreement, the DOR may revoke the plan and pursue collection measures, including levying bank accounts or intercepting state refunds. Those facing significant financial hardship may qualify for an Offer in Compromise, which allows for a reduced settlement if full payment is unlikely. However, approval requires detailed financial disclosures and is not guaranteed.