October 2026 Tax and Business Deadlines for Greater Boston

October brings several key tax deadlines for small businesses, real estate investors, and self-employed individuals across Braintree, Quincy, and greater Boston. To keep your operations running smoothly, be sure to review these upcoming dates for filing returns, depositing payroll taxes, and funding retirement plans to determine which requirements apply to your specific situation.

Accountant reviewing tax forms

October 15: Corporate Income Tax Returns

If you operate a corporation and timely requested an automatic six-month extension by April 15, your 2025 calendar year income tax return (Form 1120) is due. You must file the return and pay any remaining tax, interest, and penalties due at this time.

October 15: Payroll Tax Deposits

For businesses utilizing the monthly deposit rule for payroll, October 15 is the deadline to deposit Social Security, Medicare, and withheld income tax for payments made during September.

October 15: Nonpayroll Withholding Deposits

Similarly, if the monthly deposit rule applies to your operations, you must deposit the tax for any nonpayroll payments made in September by this date.

October 15: Establishing 2025 Keogh Accounts

If you are a self-employed professional who received an automatic six-month extension of time to file your 2025 tax return, October 15, 2026, serves as the final day to formally establish a Keogh retirement account if you plan to make a contribution for the 2025 tax year.

One Accounting Tax® Since 2017
Call/Text: (617) 829-0928 or email service@oneaccountingtax.com to schedule an in-person consultation or video call with our Tax Advisors (IRS Enrolled Agent, EA) today. Serving Braintree, Quincy, and Greater Boston with full-service accounting—tax preparation, payroll, bookkeeping, and year-round tax planning.
Contact Our Local Tax Advisors Today!

October 15: SEP IRA and Keogh Contributions

This date also marks the final deadline to actually fund your SEP IRA or Keogh retirement plan for the calendar year 2025, provided your tax return remains on extension through October 15.

Weekend and Holiday Rules

When a standard tax due date falls on a Saturday, Sunday, or legal holiday, the deadline is automatically extended to the next official business day that is not itself a legal holiday.

Disaster Area Filing Extensions

Please note that when a geographical region is officially designated as a disaster area, related tax due dates will be extended. To verify whether a specific area has received this designation and to review the revised filing extension dates, consult the following resources:

Stay Compliant This October

Managing these due dates is a vital part of effective tax preparation and bookkeeping. Whether you need assistance filing your corporate return, managing sales and meals tax filing alongside your payroll deposits, or navigating an IRS auditing inquiry, partnering with a qualified Accountant or IRS Enrolled Agent (EA) can keep your business on track. Contact our team to schedule a consultation and ensure all your October filing requirements are met.

One Accounting Tax® Since 2017
Call/Text: (617) 829-0928 or email service@oneaccountingtax.com to schedule an in-person consultation or video call with our Tax Advisors (IRS Enrolled Agent, EA) today. Serving Braintree, Quincy, and Greater Boston with full-service accounting—tax preparation, payroll, bookkeeping, and year-round tax planning.
Contact Our Local Tax Advisors Today!
Share this article...
Ask me anything! Our Ai Smart Bot Can Assist With Questions You May Have
If you'd prefer a call - click Contact Us Now below
Please fill out the form and our team will get back to you shortly The form was sent successfully