TaxZerone warns S corps and partnerships the Sept. 15 filing deadline is tomorrow

TaxZerone is urging U.S. S corporations, partnerships and tax professionals to e-file extended 2025 Form 1120-S and Form 1065 returns before the September 15, 2026 federal deadline. The warning comes as businesses that filed Form 7004 in March run out of extension time and risk IRS penalties if they miss the cutoff.

Why it matters: - The September 15, 2026 deadline is the last day for many calendar-year S corporations and partnerships that received a six-month extension to file their 2025 federal business tax returns. - Missing the deadline can trigger IRS late-filing penalties, late-payment charges, interest and Schedule K-1 penalties, depending on the filing situation. - Tax professionals handling multiple client returns have limited time to complete filings, fix errors and gather missing information before the cutoff.

What happened: - TaxZerone, an IRS-authorized e-file provider, is urging businesses and tax professionals to file extended 2025 Form 1120-S and Form 1065 returns before September 15, 2026. - The company says it helps users prepare and electronically file business returns, associated schedules and supporting forms. - TaxZerone said businesses can also generate and distribute applicable Schedule K-1s through its filing workflow.

The details: - Calendar-year S corporations and partnerships generally had a March 16, 2026 filing deadline for 2025 returns before filing Form 7004 for an extension. - Eligible filers who submitted Form 7004 on time generally received an automatic extension through September 15, 2026. - S corporations generally file Form 1120-S, U.S. Income Tax Return for an S Corporation. - Partnerships generally file Form 1065, U.S. Return of Partnership Income. - TaxZerone says its platform supports Form 1120-S and Form 1065 filings, plus related schedules and attachments. - Supported forms include Form 4797, Form 4562, Form 8825, Form 1125-A, Form 1125-E, Form 7205 and Form 8949. - For Form 1120-S filers, TaxZerone supports Schedule D, Schedule M-3, Schedule B, Schedule K, Schedule L, Schedule M-1 and Schedule M-2. - For Form 1065 filers, TaxZerone supports Schedule D, Schedule M-3, Schedule C, Schedule F, Form 8697, Form 8866, Schedule B-1, Schedule B-2 and Form 8825. - TaxZerone says all supported schedules and attachments are included at no additional cost. - The platform automatically generates applicable Schedule K-1s. - Completed K-1 information can be delivered through ZeroneVault or encrypted email. - TaxZerone lists flat fees of $179.99 per Form 1120-S return and $179.99 per Form 1065 return. - The pricing includes applicable schedules, supporting forms, automatic K-1 generation and secure distribution. - TaxZerone says it offers live chat, email and phone support for businesses and tax professionals. - The company’s broader filing platform also covers employment tax forms, information returns, business tax forms, extension requests, nonprofit filings, excise tax filings and essential forms. - TaxZerone says users can file business tax forms online at TaxZerone.com or call (408) 444-7120 for assistance.

Between the lines: - The message is aimed at filers facing the most common end-of-extension bottleneck: returns that are ready in substance but still need final review, schedules or K-1 distribution. - TaxZerone is using the deadline to highlight speed, bundled support and fixed pricing as a way to reduce last-minute filing friction. - The penalty reminders underscore why late coordination between business owners, accountants and tax preparers can become costly even when the underlying tax liability is limited or passes through to owners.

What's next: - Businesses that have not yet filed must complete and transmit their federal returns immediately if they want to avoid the deadline. - Tax professionals are likely to spend the final hours prioritizing remaining extended returns and related K-1s. - Any filer who misses the deadline will need to rely on penalty relief or other exceptions, if available, based on their circumstances.

The bottom line: - For many S corporations and partnerships, tomorrow is the last chance to close out their 2025 federal filing obligations without added penalties.