Tax Season 2026 is Here: What Do You Need to Know?

With tax season now underway, many of our clients are asking the same question: What do I need to know to make this process go smoothly? For most of the clients we serve, tax filings are connected, whether that connection is between a business and its owners, multiple entities, or trusts and estates tied to family or ownership responsibilities. This article provides a practical overview of what to expect during the 2026 tax filing season, along with a few reminders that may help keep things on track.

What’s Shaping This Filing Season

As with every filing season, there are a few factors influencing the process this year.

Because there is new tax legislation impacting 2025 returns and the IRS continues to operate with reduced staffing levels and tighter budgets, processing times and correspondence will be greatly impacted. These factors don’t change filing requirements, but they do make organization, preparation, and timely communication more important, particularly when multiple returns or related filings are involved. Keep in mind that when information is complete and provided on a timely basis, the process can run more smoothly and surprises or long wait times may be minimized.

Key Dates to Keep in Mind

For clients with a December 31 year end, the primary federal filing deadlines are:

• March 16, 2026 — S Corporations and Partnerships (including most LLCs)
• April 15, 2026 — Individuals, Trusts, Sole Proprietors, and C Corporations

Because some filings depend on others, (for example, business returns often drive owner or fiduciary filings) timing matters.

To allow adequate time for our review and follow-up questions, we ask that all necessary information be provided to us by:

• February 16, 2026 for March 16 filings
• March 16, 2026 for April 15 filings

If additional time is needed, extensions are available. Please note that an extension to file is not an extension to pay, so advance planning is important if a balance may be due.

Engagement Letters and Getting Started

You may hear your BMSS team refer to MSELs and Statements of Work. These are our engagement letters and are sent via email through our secure platform, Knuula.

Many clients have already received — and signed — their engagement letters. If your engagement letters are still outstanding, completing them allows us to schedule your work, coordinate related filings, and begin planning without delays.

How to Provide Information

Another important part of the process to consider is how to provide your BMSS professional with your information.

• For business-related as well as trust and estate information, your BMSS team will work with you to determine the appropriate electronic method for gathering financial and tax information.
• For individuals, documents can be uploaded through your Tax Caddy account. Please reach out to your BMSS team for information on setting this up.

Using these tools helps ensure we receive complete information across all related filings, including items that are easy to overlook, such as:

• New income or investments;
• Ownership or allocation changes;
• Transactions that affect more than one return; or
• Life events that impact tax reporting.

Communication Matters

Each client is supported by a dedicated BMSS team, and that team should be your first point of contact if questions come up or when there are developments that could impact your tax situation.

One of the most common challenges we see each year is incomplete or delayed information, which can create ripple effects across related returns. As stated earlier, providing your complete tax information to us in a timely manner is beneficial for everyone.

We do expect you will have questions, especially given the changes brought about by new tax legislation. Early communication often provides more flexibility and helps avoid surprises.

Paper Filing, Postmarks, and USPS Rule Changes

For clients who file paper returns or mail payments, it’s important to be aware of recent changes to USPS postmark rules.

Although a return or payment is generally treated as timely filed if it is mailed by the due date, USPS rules, effective December 2025, clarify that a postmark date may not always reflect the date the item was placed in the mail. Under these rules, the postmark may reflect a later processing date instead.

This means that placing a return or payment in a mailbox on the due date does not guarantee a postmark with that date.

To reduce risk:

• Electronic filing and payments are recommended whenever possible.
• If paper filing is required, you can request a manual postmark at the post office.
• Use certified or registered mail for proof of timely mailing.

If paper filing or mailing payments are being considered, please contact your BMSS team in advance.

Refunds and Payments

The IRS continues to move toward electronic payments and direct deposit, particularly following the executive order on modernizing payments to and from America’s bank accounts.

Paper checks are still accepted at this time,but taxpayers should be aware that they are expected to be phased out in the future as the IRS continues this transition.  Planning ahead for electronic options can help avoid disruptions down the road.

• For refunds, confirming direct deposit information helps avoid delays.
• For balances due, electronic options such as IRS Direct Pay are often the most efficient.

Please keep in mind that payment considerations can differ depending on whether a return is business-related, individual, or fiduciary. Your BMSS team can help talk through the options.

Looking Ahead

Tax filings are only one part of the ongoing decisions our clients manage throughout the year. Through the BMSS Family of Companies, including BMSS Advisors & CPAs, Abacus Technologies, Payroll & Benefit Solutions, and BMSS Wesson Wealth Solutions, we support those decisions across tax, accounting, financial reporting, transaction advisory, technology, payroll, estate planning, wealth management, and many other needs.

As tax season progresses, conversations about upcoming changes, whether business, personal, or fiduciary, can be helpful in keeping planning and reporting aligned. We appreciate the opportunity to work with you and look forward to supporting you through the remainder of the 2026 tax season and into the future. For questions or to reach out to your BMSS team, please call (833) CPA-BMSS or visit our website for more information.