The September tax deadline , particularly on the 15th, is fundamental for partnerships and S-Corporations. This date marks the due submissions for Form 1065 and Form 1120S , critical filings that help you avoid hefty penalties. If you filed for an extension in March, missing this deadline can lead to a 5% monthly penalty and a $255 fine for each partner or shareholder. Comprehending these implications is important for maintaining your business’s financial health. What steps can you take to guarantee compliance? Key Takeaways September 15 is the deadline for partnerships and S-Corporations to file tax returns using Form 1065 and Form 1120S. Late filings incur penalties of $255 per partner or shareholder each month, plus a 5% monthly penalty on unpaid taxes. Timely filing helps avoid interest charges on owed taxes and ensures compliance with IRS regulations. Proactive planning, like reviewing previous returns and gathering financial documents, can reduce complications.…