What You Need to Know

If you own an S Corporation (S-Corp), the annual federal tax filing deadline is March 15.

S-Corps don’t pay federal income taxes directly. Instead, profits and losses pass through to the owners’ personal tax returns, where they are reported and taxed. This allows for potential tax savings but also means your business return (Form 1120-S) needs to be completed before, or alongside, your personal return.

Federal Tax Obligations

All taxes flow through to the owners’ personal tax returns.

State Tax Obligations

While the federal government doesn’t tax S-Corp income at the corporate level, state tax obligations can vary. Most states align with the federal deadlines and offer automatic extensions alongside the federal ones.

Some states impose taxes or fees on S-Corps, which may also be due by March 15. For example:

•California: Requires S-Corps to pay a franchise tax, which is the greater of 1.5% of net income or a minimum tax of $800. The due date aligns with the federal deadline—March 15.

•New York: There is a fixed dollar minimum tax based on the corporation’s New York receipts.

•Minnesota: Requires S-Corps to pay a minimum fee based on property, payroll, and sales factors.  This applies above a sales threshold of 1,160,000.  The state return is due by March 15.

Because S-Corp profits and losses flow to your personal tax return, it’s best to review both together. Your Schedule K-1, which reports your share of business income, deductions, and credits, is a key document for completing your individual return.

If you’re not ready to file by March 15, and many of us aren’t, you can file an extension, giving you until September 15 to submit your S-Corp return. However, this does not extend the time to pay taxes owed.  You still need to estimate and pay any tax liability to avoid penalties and interest.

To stay on track, work with your accountant to finalize your books, review your tax position, and ensure all necessary documents are in order. Whether you’re filing by the deadline or requesting an extension, keeping your S-Corp and personal tax filings aligned will help you avoid surprises and stay compliant.

What if March 15 falls on a weekend?

Tax deadlines apply to the working day following the annual deadline.  If the March 15 falls on a Saturday, the deadline will normally be the following Monday.

Pair S-corp and personal returns

We often recommend reviewing the business returns together with your personal return.  It’s common to go on extension for business, personal, or both, to make sure these can be seen holistically by the business owner and their tax preparer.  There’s no additional cost for this when you work with us.