Common Tax Myths Business Owners Believe (And What the IRS Actually Says)

Most small business tax myths aren’t invented. They’re outdated rules, half-remembered advice, or something that was true for a different kind of business. At SD Associates, P.C., our CPAs in Elkins Park, PA have spent 43 years correcting the same small business tax misconceptions for owners across Philadelphia, Bucks, and Montgomery counties. Here are the costliest ones, and what the rules actually say.

Key Takeaways

• Do I need to file taxes if my business lost money? Usually yes—corporations and partnerships file regardless of profit
• An extension moves your filing deadline, not your payment deadline
• Income is reportable whether or not a form arrives in the mail
• Philadelphia ended its $100,000 BIRT exemption, so your local filing obligations changed even if your federal ones didn’t

Why Small Business Tax Myths Get Expensive

A tax myth doesn’t cost you anything the day you believe it. It costs you when a deadline passes. By the time a notice arrives, you’re paying for a decision made months earlier. That’s what separates these from ordinary common tax mistakes—they compound quietly.

Do I Need to File Taxes If My Business Lost Money?

Usually, yes. This is the most common of the small business tax misconceptions that SD Associates, P.C. sees from newer owners. Your filing requirement depends on your entity:

• C corporations and S corporations: file every year, regardless of profit
• Partnerships: file whenever there is income or expenses
• Sole proprietors: file when net self-employment earnings reach $400

Skipping a loss year also costs you. Filing is what documents the loss for future years and starts the clock on the IRS statute of limitations. An unfiled year stays open indefinitely.

Does a Tax Extension Extend Time to Pay?

No. An extension gives you more time to file your paperwork—nothing else. The IRS is unambiguous: an extension to file is not an extension to pay.

The penalties make this distinction obvious:

• Failure to file: 5% of unpaid tax per month, capped at 25%
• Failure to pay: 0.5% per month, capped at 25%

Filing an extension stops the larger penalty, but interest and the failure-to-pay penalty keep running on whatever you owe. So when a client asks, “Does a tax extension extend time to pay?” our answer is the same every time: file the extension, then pay your best estimate by the original deadline. Here’s what happens when a business doesn’t pay on time.

Is Income Taxable If I Never Received a 1099?

Yes. Information returns exist to report income to the IRS, not to create the obligation. If a client paid you and never issued a form, that payment belongs on your return exactly the same way.

The practical problem is reconciliation. Your books are the authoritative record of what came in, and when owners rely on arriving forms to reconstruct a year, the numbers rarely match. Build the return from your own records, then use the forms as a cross-check—not the reverse.

Do Philadelphia Businesses Under $100,000 Still Skip BIRT?

No—and this rule is local, not federal. Philadelphia ended its $100,000 statutory Business Income & Receipts Tax (BIRT) exemption beginning with tax year 2025. Every business operating in the city now files a BIRT return regardless of sales, and businesses with an active Philadelphia tax account must file even with no activity for the year.

The detail that surprises owners: the gross receipts portion is based on sales, not profit. A business that lost money can still owe the gross receipts portion. Federal rules and city rules are separate systems, and assuming one covers the other is among the tax mistakes to avoid this filing season.

Common Tax Mistakes to Avoid Year-Round

• Treating your bookkeeping software’s output as a finished return
• Running personal expenses through the business account
• Missing quarterly estimates because last year’s bill was small
• Waiting until March to ask a tax planning question that needed answering in September

FAQs

Does forming an LLC automatically lower my tax bill?

No. An LLC is a legal structure, not a tax classification. By default, single-member LLCs are taxed as sole proprietorships and multi-member LLCs as partnerships—the same income, taxed the same way. Savings come from a deliberate election and reasonable compensation analysis, not from the formation itself.

If my CPA prepares my return, am I still responsible for errors?

Yes. You sign the return under penalty of perjury, which makes you legally responsible for its contents. A CPA reduces the chance of an error substantially and can represent you if questions arise, but the signature is yours.

Do I need a separate extension form for my Philadelphia BIRT return?

No. Philadelphia does not require businesses to submit a filing extension form for the BIRT. Any tax owed is still due by the original deadline, which follows the same logic as federal extensions.

Are estimated payments optional if I pay the full amount in April?

No. The system expects tax to be paid throughout the year. Underpayment penalties can apply even when the balance is paid in full by the deadline, because the issue is timing, not the final amount.

Get Straight Answers From a CPA Firm That Has Heard Every Tax Myth

Tax myths survive because they sound reasonable and nobody checks them until a notice arrives. SD Associates, P.C. has been separating them from the actual rules for business owners in Philadelphia and throughout the Tri-State area since 1983, and we’re always reachable by phone or email when a question can’t wait.

Whether you need tax services, a second opinion on a filing position, or help correcting a prior-year filing, we can help. Schedule your free consultation today.