Important Tax Dates

Navigating the complexities of tax season is crucial for timely and accurate financial management.This page provides an extensive calendar covering all essential federal and State of Montana tax deadlines, as well as crucial dates specific to our firm. This resource is designed to keep you informed and prepared, ensuring that all materials are submitted on time for a stress-free tax filing experience. Keep this page bookmarked for easy reference and stay on top of your financial obligations with ease.

Due DateAction
January 12thEmployers: Employees are required to report to you tips of $20 or more earned during December 2025. Use Form 4070
January 15th

Submit your W-2 and/or 1099 information to your assigned Swensen, Phelan & Associates office to guarantee a timely filing of your forms

Deposit payroll tax for Dec 2025 if the monthly deposit rule applies.

Individuals: Pay the final installment of your 2025 estimated tax - use Form 1040-ES or pay online here

Farmers and fishermen: Pay your estimated tax for 2025. Use Form 1040-ES or pay online here

February 2nd

Deposit any FUTA tax owed through Dec 2025

File Form 1099-NEC for nonemployee compensation paid in 2025, see instructions

File Forms 940, 941, 943, 944, and/or 945 if you did not deposit all taxes when due

Furnish Forms 1098, 1099, & W-2G to recipients for certain payments during 2025

Employers: Furnish Form W-2 to employees who worked for you in 2025 & file Form W-3, Transmittal of Wage & Tax Statements, with Copy A of Forms W-2 you issued for 2025.

File Form 2290 and pay the tax for vehicles first used in December 2025.

February 10th

Employers: Employees are required to report to you tips of $20 or more earned during January 2026. Use Form 4070

February 17th

Submit your Partnership or S Corporation information to your assigned Swensen, Phelan & Associates office to guarantee a timely filing of your tax returns

Deposit payroll tax for January if the monthly deposit rule applies

Employees: File a new Form W-4 with your employer if you claimed exemption from income tax withholding in 2025

Employers: Begin withholding on employees who claimed exemption from withholding in 2025 but did not file a W-4 to continue withholding exemption in 2026

March 2nd

File Form 1096 with information returns, including Forms 1098, 1099 and W-2G for payments made during 2025

File Form 2290 and pay the tax for vehicles first used in January 2026

File paper Forms 1094-C and 1095-C with IRS if you are an Applicable Large Employer; For all other providers file paper Forms 1094-B and 1095-B with the IRS

March 3rd

Contact your assigned Swensen, Phelan & Associates office to request an extension of time to file your Partnership or S-Corporation tax return

Applicable Large Employers provide Forms 1095-C to full-time employees; for all other providers of Minimum Essential Coverage, provide Forms 1095-B to responsible individuals

Farmers and fishermen: File Form 1040 and pay any tax due. However, you have until April 15th to file if you paid your 2025 estimated tax payments by January 15, 2026.

March 10th

Employers: Employees are required to report to you tips of $20 or more earned during February. Use Form Form 4070

March 16th

Submit your Individual, C-Corporation, or Estate or Trust information to your assigned Swensen, Phelan & Associates office to guarantee a timely filing of your tax returns

Deposit payroll tax for February if the monthly deposit rule applies

Partnerships: File Form 1065 for calendar year 2025 and furnish a copy of Schedule K-1 or K-3 to each partner. For automatic 6-month extension, file Form 7004 There is no additional extension of time to file after this 6-month extension

S Corp: File Form 1120S for calendar year 2025 and pay any tax due. Furnish a copy Schedule K-1 or K-3 to each shareholder. For automatic 6-month extension, file Form 7004. There is no additional extension of time to file after this 6-month extension

File Form 2553 to elect S Corporation status beginning with calendar year 2026

March 31st

File Form 2290 and pay the tax for vehicles first used in February 2026

April 8th

Estimates for payment with extensions start today. Make sure you’ve contacted your assigned Swensen, Phelan & Associates office if you want to make a payment with your extension of time to file

April 10th

Employers: Employees are required to report to you tips of $20 or more earned during March. Use Form 4070

April 15th

Corporations: File Form 1120 for calendar year 2025 and pay any tax due. For automatic 6-month extension, file Form 7004. There is no additional extension of time to file after this 6-month extension

Estates and Trusts: File Form 1041 for calendar year 2025 and pay any tax due. For automatic 6-month extension, file Form 7004. There is no additional extension of time to file after this 6-month extension

Individuals: File Form 1040 or 1040SR for calendar year 2025 and pay any tax due. For automatic 6-month extension file Form 4868 There is no additional extension of time to file after this 6-month extension

Household Employers: File Sch. H with Form 1040 if you paid cash wages of $2,700 or more to a household employee

Deposit payroll tax for March if the monthly deposit rule applies

Deposit First installment of estimated tax payments for Individuals and C-Corporations

S-Corporations and Partnerships: Pay the first installment of your 2026 Pass-Through Entity Tax (PTET) online. Click Make a Payment under Quick Links

April 30th

Deposit FUTA tax owed through March if more than $500

Employers: File Form 941 for the first quarter

File Form 2290 and pay the tax on vehicles first used in March 2026

May 11th

Employers: Employees are required to report to you tips of $20 or more earned during April. Use Form 4070

June 1st

File Form 2290 and pay the tax for vehicles first used during April 2026

June 15th

Deposit Second installment of estimated tax payments for Individuals and C-Corporations

S-Corporations and Partnerships: Pay the Second installment of your 2026 Pass-Through Entity Tax (PTET) online. Click Make a Payment under Quick Links

Deposit payroll tax for May if the monthly deposit rule applies

June 30th

File Form 2290 and pay the tax for vehicles first used during May 2026

July 10th

Employers: Employees are required to report to you tips of $20 or more earned during June. Use Form 4070

July 15th

Deposit payroll tax for June if the monthly deposit rule applies

July 31st

Deposit FUTA owed through June if more than $500

File Form 941 for the second quarter of 2026

File Form 2290 and pay the tax for vehicles first used during June 2026

File Form 5500, 5500-EZ, 5500-SF, 5558, or 8955-SSA for calendar year 2025 employee benefit plan. See Form 5500 Corner on IRS for information.

August 3rd

Submit your Partnership or S Corporation information to your assigned Swensen, Phelan & Associates office to guarantee filing of your tax returns by the extended due date

August 10th

Employers: Employees are required to report to you tips of $20 or more earned during July. Use Form 4070

August 17th

Deposit payroll tax for July if the monthly deposit rule applies

August 31st

File Form 2290 and pay the tax for vehicles first used during July 2026

September 1st

Submit your Individual, C-Corporation, or Estate or Trust information to your assigned Swensen, Phelan & Associates office to guarantee filing of your tax returns by the extended due date

September 10th

Employers: Employees are required to report to you tips of $20 or more earned during August. Use Form 4070

September 15th

Partnerships: File calendar year 2025 Form 1065 if you timely requested a 6-month extension. There is not another extension of time to file

Corporations: File calendar year 2025 Form 1120S if you requested a 6-month extension in the time. There is not another extension of time to file

Deposit third installment of estimated tax payments for Individuals and C-Corporations

S-Corporations and Partnerships: Pay the third installment of your 2026 Pass-Through Entity Tax (PTET) online. Click Make a Payment under Quick Links

Deposit payroll tax for August if the monthly deposit rule applies

September 30th

File Form 2290 and pay the tax for vehicles first used during August 2026

October 1st

Contact your assigned Swensen, Phelan & Associates office to schedule year-end tax planning if applicable

October 13th

Employers: Employees are required to report to you tips of $20 or more earned during September. Use Form 4070

October 15th

Individuals: File Form 1040 if you timely requested a 6-month extension. There is not another extension of time to file

Corporations: File calendar year 2025 Form 1120 if you timely requested a 6-month extension. There is not another extension of time to file

Deposit payroll tax for September if the monthly deposit rule applies

November 2nd

Deposit FUTA taxes owed through September if more than $500

File Form 941 for the third quarter of 2026

File Form 2290 and pay the tax for vehicles first used during September 2026

November 10th

Employers: Employees are required to report to you tips of $20 or more earned during October. Use Form 4070

November 16th

Deposit payroll tax for October if the monthly rule applies

November 30th File Form 2290 and pay the tax for vehicles first used during October 2026
December 10thEmployers: Employees are required to report to you tips of $20 or more earned during November. Use Form 4070
December 15th

Deposit fourth installment of estimated tax payments for C-Corporations. Although not due until January 15, 2027, it may be beneficial for individuals to also deposit their fourth installment of estimated payments

S-Corporations and Partnerships: pay the fourth installment of your 2026 Pass-Through Entity Tax (PTET) online. Click Make a Payment under Quick Links

Deposit payroll tax for November if the monthly deposit rule applies

December 31stFile Form 2290 and pay the tax for vehicles first used during November 2026

Navigating the complexities of tax filing can be challenging. If you find yourself in need of guidance or have questions about the tax-filing process, our experienced team is here to help. Contact us for personalized assistance and ensure a smooth and stress-free tax season.