Resources & Insights

Research library.

A curated collection of IRS forms, publications, Circular 230, Massachusetts guidance, and deadline calendars. All links go to official .gov sources.

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IRS Forms

Direct links to fillable PDF forms on IRS.gov

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IRS Publications

Authoritative IRS guides for individuals and businesses

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Circular 230

The regulation governing practice before the IRS

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MA DOR

Massachusetts Department of Revenue — TIRs, directives

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Tax Deadlines

Key dates for individual and business filers

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Newsroom

Selected IRS news and recent guidance

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IRS Forms

Fillable PDFs · IRS.gov
Form 1040
U.S. Individual Income Tax Return
 Form 1040-SR
U.S. Tax Return for Seniors
 Form 1040-ES
Estimated Tax for Individuals
 Form 1040-X
Amended U.S. Individual Income Tax Return
 Form 1040-NR
U.S. Nonresident Alien Income Tax Return
 Schedule A
Itemized Deductions
 Schedule B
Interest and Ordinary Dividends
 Schedule C
Profit or Loss from Business
 Schedule D
Capital Gains and Losses
 Schedule E
Supplemental Income and Loss
 Schedule SE
Self-Employment Tax
 Form 8949
Sales and Other Dispositions of Capital Assets
 Form 2555
Foreign Earned Income
 Form 1116
Foreign Tax Credit
 Form 8938
Statement of Foreign Financial Assets
 Form W-7
Application for ITIN
 Form 1120
U.S. Corporation Income Tax Return
 Form 1120-S
U.S. Income Tax Return for an S Corporation
 Form 1065
U.S. Return of Partnership Income
 Form 1041
U.S. Income Tax Return for Estates and Trusts
 Form 941
Employer's Quarterly Federal Tax Return
 Form 940
Employer's Annual Federal Unemployment (FUTA)
 Form 2848
Power of Attorney
 Form 8821
Tax Information Authorization
 Form 9465
Installment Agreement Request
 Form 656
Offer in Compromise
 Form 843
Claim for Refund / Abatement
 Form 4868
Extension — Individual
 Form 7004
Extension — Business
 FinCEN 114
Report of Foreign Bank Accounts (FBAR)

IRS Publications

Plain-language guides · IRS.gov
Pub 17
Your Federal Income TaxThe comprehensive individual tax guide for most common situations.
 Pub 1
Your Rights as a TaxpayerThe Taxpayer Bill of Rights — 10 fundamental rights.
 Pub 334
Tax Guide for Small BusinessSchedule C, self-employment tax, and estimated payments.
 Pub 463
Travel, Gift, and Car ExpensesDeductible business travel, standard mileage, and per diem.
 Pub 501
Dependents & Standard DeductionFiling status, dependency tests, and standard deduction rules.
 Pub 502
Medical and Dental ExpensesWhat qualifies for the Schedule A medical deduction.
 Pub 505
Tax Withholding and Estimated TaxCalculating and making quarterly estimated payments.
 Pub 523
Selling Your HomeHome sale exclusion, basis, and reporting requirements.
 Pub 526
Charitable ContributionsDeductibility rules, substantiation, and limits.
 Pub 527
Residential Rental PropertyIncome, deductions, depreciation, and passive activity rules.
 Pub 535
Business ExpensesDeductibility of ordinary and necessary business costs.
 Pub 550
Investment Income and ExpensesDividends, interest, capital gains, and investment interest.
 Pub 587
Business Use of Your HomeHome office deduction — Form 8829 and simplified method.
 Pub 590-A
IRAs — ContributionsTraditional and Roth IRA contribution rules and limits.
 Pub 590-B
IRAs — DistributionsIRA distribution rules, RMDs, and inherited IRA treatment.
 Pub 946
How to Depreciate PropertyMACRS, §179 expensing, bonus depreciation, and Form 4562.
 Pub 15
Employer's Tax Guide (Circular E)Withholding tables, deposit rules, and Form 941.
 Pub 15-B
Fringe Benefits GuideTaxability of health, transportation, and other fringe benefits.
 Pub 541
PartnershipsFormation, operations, distributions, K-1, and basis rules.
 Pub 542
CorporationsC-Corp taxation, dividends, accumulated earnings, and AMT.
 Pub 556
Examination, Appeal RightsAudit process, documentation, and how to appeal IRS decisions.
 Pub 594
The IRS Collection ProcessOverview of IRS collection actions, rights, and options.
 Pub 971
Innocent Spouse ReliefThree types of relief from joint and several liability.
 Circular 230
Regulations Governing Practice Before the IRSStandards of conduct for Enrolled Agents and tax practitioners.

Circular 230

31 C.F.R. Part 10

Circular 230 is the federal regulation that governs practice before the IRS — the standards of conduct every Enrolled Agent, CPA, and attorney admitted to practice must follow.

It covers power of attorney rules, due diligence in preparing and advising on tax matters, conflicts of interest, competence, fee rules (including the prohibition on contingent fees for most tax-return work under §10.27), and the disciplinary sanctions Treasury may impose for violations.

Key Sections

  • §10.22 — Due diligence in preparation of returns and other papers
  • §10.27 — Fees; prohibition on contingent fees for tax returns
  • §10.29 — Conflicting interests
  • §10.33 — Best practices for tax advisors
  • §10.34 — Standards with respect to tax returns
  • §10.35 — Competence
  • §10.51 — Incompetence and disreputable conduct

Massachusetts DOR

mass.gov · Official

MA DOR Home

Massachusetts Department of Revenue — the official home for state tax administration.

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Technical Information Releases (TIRs)

DOR's formal interpretive statements on Massachusetts tax law changes and guidance.

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DOR Directives

DOR directives setting forth the Commissioner's position on tax administration matters.

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MassTaxConnect

Massachusetts online portal for filing, paying, and managing state tax accounts.

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MA Personal Income Tax Forms

Form 1, Form 1-NR/PY, and all Massachusetts personal income tax forms and instructions.

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MA Business Tax Forms

Form 355, Form 355S, Form 3, and other Massachusetts business tax forms.

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Tax Deadlines Calendar

Federal & Massachusetts · Calendar-year filers

A comprehensive annual calendar of federal and Massachusetts filing deadlines for individuals, businesses, nonprofits, and employers. Dates shown are for calendar-year filers; fiscal-year filers should adjust accordingly.

DateEvent
January
January 15Q4 estimated tax payment due (prior year) — Form 1040-ES
January 31W-2 and 1099-NEC forms due to recipients and to SSA/IRS
January 31Form 940 (FUTA) annual return — federal unemployment tax
January 31Form 941 (Q4) employer’s quarterly federal tax return
January 31Form 945 annual return of withheld federal income tax
January 31Massachusetts employer quarterly wage reports (PFML & UI)
February
February 15Reclaim withholding exemption (Form W-4 refile, if applicable)
February 281099 forms (other than NEC) paper-filing deadline to IRS
March
March 15S-Corp (Form 1120-S) and Partnership (Form 1065) returns due
March 15Form 7004 extension request for 1120-S / 1065 (6 months)
March 311099 forms (other than NEC) electronic-filing deadline
March 31Form 1096 (annual information-return transmittal, if filed on paper)
April
April 15Individual Form 1040 and C-Corp Form 1120 returns due
April 15Q1 estimated tax payment due (Form 1040-ES / Form 1120-W)
April 15Form 1041 (trust and estate income-tax return) due
April 15Form 4868 automatic 6-month extension for individuals
April 15FBAR (FinCEN Form 114) due — automatic extension to October 15
April 15IRA and HSA contributions deadline for prior year
April 15Form 709 gift-tax return (or extension) due
April 15Form 990-T due for trusts (employee-plan, IRA)
April 15Massachusetts Form 1 individual return due
April 30Form 941 (Q1) employer’s quarterly federal tax return
May
May 15Form 990 series due for calendar-year exempt organizations
May 15Form 8868 extension for Form 990 (6 months, to Nov 15)
May 15Massachusetts Form PC due for calendar-year public charities
June
June 15Q2 estimated tax payment due
June 15Expat 1040 deadline — automatic 2-month extension for taxpayers abroad
June 30PFML quarterly contribution filing (MA)
July
July 31Form 941 (Q2) employer’s quarterly federal tax return
July 31Form 5500 (employee benefit plan) due for calendar-year plans
September
September 15Q3 estimated tax payment due
September 15Extended S-Corp (1120-S) and Partnership (1065) returns due
September 30Extended fiduciary Form 1041 returns due
October
October 15Extended Form 1040 and C-Corp Form 1120 returns due
October 15Extended FBAR (FinCEN 114) due
October 15Extended Form 709 gift-tax return due
October 31Form 941 (Q3) employer’s quarterly federal tax return
November
November 15Extended Form 990 series due for calendar-year exempt organizations
November 15Extended Massachusetts Form PC due
December
December 15Q4 estimated tax payment due for C-Corps (Form 1120-W)
December 31Deadline for most year-end tax-planning actions (RMDs, Roth conversions, charitable gifts)

When a deadline falls on a Saturday, Sunday, or legal holiday, the deadline generally moves to the next business day. Consult the IRS Tax Calendar for authoritative current-year dates.

Newsroom

Curated · Updated periodically

Selected IRS news items of general interest. For live updates, subscribe to IRS Newswire directly, or sign in to the Client Portal for our curated client-alert feed.

IRS Newsroom

The IRS's official newsroom — press releases, tax tips, and current-year announcements.

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Curated client alerts, legislation tracking, and research summaries — inside the Client Portal.

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