This article covers the key dates for the 2026 tax season, meaning your 2026 tax year returns filed in 2027. It applies to S Corp tier members. If you're an LLC tier member, see Key 2026 Tax Season Milestones for LLC Members.
As an S Corp owner, you have two federal returns. Your business files a Business Tax Return (BTR) on Form 1120-S, the S Corp business tax return, and you file an Individual Tax Return (ITR) for your personal income. Your BTR produces your Schedule K-1, which reports your share of business income. Your ITR can't be completed without it, so the business return always comes first.
Why these milestones matter
Your return is only as accurate as the books behind it. Each milestone builds on the one before: complete books lead to an accurate organizer, and an accurate organizer leads to a return you can approve with confidence. Finishing each step on time keeps your BTR on track for the March deadline and gets your K-1 to your ITR sooner.
The milestones below follow the same three stages you'll see in your 2026 tax tracker in the Collective dashboard.
Stage 1: 2026 financial overview (now through December 31, 2026)
This stage is about getting a complete picture of your year before it ends, so your Collective team can fix any gaps before the holidays.
| Date | Milestone | What to do |
|---|---|---|
| Now | Get started | Connect every business account to Collective and send any missing statements. Missing accounts are the most common reason books can't be finalized on time. |
| December 12, 2026 | Run payroll (if applicable) | If you haven't run payroll for yourself yet in 2026, it must be run by this date. As an owner-employee, paying yourself a reasonable salary through payroll is part of what keeps your S Corp set up the way the IRS expects, and running it before year-end means it's reported for 2026. |
| December 31, 2026 | Check accounts and reimburse | Confirm all accounts are connected and up to date. If you paid for business expenses personally, submit them for reimbursement through your accountable plan (the IRS-approved way for your S Corp to pay you back for business costs) so they're recorded in 2026. |
Joined Collective after November 1, 2026? Your 2026 BTR will be filed on extension so there's time to complete your books. Your Collective team will share your timeline.
Stage 2: Review deductions (January through February 1, 2027)
Once the year closes, you'll confirm your numbers and tell us about your year. When both steps are done, we start your return.
| Date | Milestone | What to do |
|---|---|---|
| January 29, 2027 | Approve books | Review and approve your 2026 Profit and Loss statement and Balance Sheet in your dashboard. |
| February 1, 2027 | Submit organizer | Complete your Business Organizer, a short set of questions about your year. Once your books are approved and your organizer is submitted, Collective starts your return. |
Missed these dates? If your books aren't approved and your organizer isn't submitted by February 1, Collective will file an extension for both your BTR and ITR by February 5, 2027. An extension gives you more time to file, not more time to pay.
Stage 3: Approve and file (March 2027)
| Date | Milestone | What to do |
|---|---|---|
| March 13, 2027 | Sign return | Review your draft BTR, approve it, and sign the e-file authorization so we can file for you. |
| March 15, 2027 | File return | Federal BTR filing deadline. Collective files your Form 1120-S as part of your S Corp tier membership. Pay any taxes due, if applicable. S Corps generally don't owe federal income tax, but some states charge their own tax or fees. |
If your BTR is extended
| Date | What to do |
|---|---|
| March 15, 2027 | Pay any taxes due, even with an extension. Your Collective team can help estimate an extension payment, if applicable. |
| August 31, 2027 | Approve your books and submit your Business Organizer. |
| September 13, 2027 | Approve and sign your return. |
| September 15, 2027 | Extended BTR filing deadline. After this date, the IRS may charge late-filing penalties. |
Your Individual Tax Return
If your membership includes your ITR, these dates apply. Because your ITR needs the K-1 from your BTR, an extended BTR means your ITR will be extended too.
| Date | Milestone | What to do |
|---|---|---|
| March 15, 2027 | Submit organizer | Complete your Individual Tax Organizer, upload supporting documents, and answer any outstanding questions. |
| April 13, 2027 | Sign return | Review your draft ITR, approve it, and sign the e-file authorization. |
| April 15, 2027 | File return | Federal ITR filing and payment deadline. Pay any taxes due, if applicable. Once you approve your return, Collective files it for you. |
Missed the organizer date? Your ITR will be extended to October 15, 2027. Any taxes due must still be paid by April 15 to avoid penalties and interest.
If your ITR is extended
| Date | What to do |
|---|---|
| April 15, 2027 | Pay any taxes due, even with an extension. |
| September 24, 2027 | Submit your completed Individual Tax Organizer and documents. |
| October 13, 2027 | Approve and sign your return. |
| October 15, 2027 | Extended ITR filing deadline. After this date, penalties and interest may apply. |
State deadlines to know about
Some states have their own deadlines that don't follow the federal schedule, and some can't be extended. These apply only if your business is registered or operates in the state listed. Rules and amounts vary and can change, so check with your state or your Collective team if you're unsure.
| Date | State | What to know |
|---|---|---|
| December 31, 2026 | Pass-through entity tax (PTET) states | Many states let S Corps elect to pay state income tax at the business level, called a pass-through entity tax (PTET). Election deadlines vary widely, and some states, such as Utah, require the election and payment by year-end. If you're considering PTET, reach out to your Collective team before December 31. |
| March 15, 2027 | California | California S Corps owe a minimum franchise tax (currently $800). The return can be extended, but the minimum tax must be paid by March 15. |
| March 15, 2027 | New York | New York S Corps file a state corporate franchise tax return. To extend it, an extension request and estimated payment are due by March 15. |
| May 1, 2027 | Florida | Annual report due through Sunbiz. There's no extension, and late filings carry a fee. |
| May 15, 2027 | Texas | Public Information Report (PIR) due, even if your business owes no franchise tax. Collective doesn't file this report, so you'll need to file it yourself through the Texas Comptroller's website. |
| June 1, 2027 | Delaware | Annual LLC franchise tax due. There's no extension, and late payments carry a penalty and interest. |
Next steps
To get started, head to your 2026 tax tracker in your Collective dashboard and connect any missing accounts. For more on extensions, see Business Tax Extensions for S Corps. If you have questions specific to your business, reach out to your Collective team. They're here to help.
This content is for informational purposes only and is not legal, financial, or tax advice. Deadlines listed reflect Collective's operational requirements to ensure timely delivery of services. Failure to meet these deadlines may result in delays to your tax filings and IRS penalties and interest, for which Collective is not responsible.