Corporate Tax Filing Deadline Reminder
Calculate key US tax deadlines for your corporation based on your fiscal year end.
Your Filing Deadlines
Your deadlines will appear here.
Complete the form and click "Calculate".
Understanding Corporate Tax Deadlines in the USA
Tax deadlines are crucial for maintaining compliance and avoiding penalties. The specific dates depend on your business structure and fiscal year end date.
S Corporations & Partnerships
- Primary Deadline (Forms 1120-S, 1065): The due date for filing the business tax return is the 15th day of the 3rd month after the end of the company's fiscal year.
- Example: For a business with a December 31st fiscal year end, the deadline is March 15th.
- Extension: A 6-month extension can be requested by filing Form 7004, which moves the deadline to September 15th (for a Dec 31st year-end).
C Corporations
- Primary Deadline (Form 1120): The due date for filing is the 15th day of the 4th month after the end of the company's fiscal year.
- Example: For a C-Corp with a December 31st fiscal year end, the deadline is April 15th.
- Extension: A 6-month extension can also be requested using Form 7004, moving the deadline to October 15th (for a Dec 31st year-end).
Important Note on Weekends & Holidays
If a tax deadline falls on a Saturday, Sunday, or a legal holiday observed in the District of Columbia (like Emancipation Day), the deadline is automatically moved to the next business day. This tool automatically adjusts for these occurrences.
${calculatedData.originalDeadline}
`; extensionCard.innerHTML = `Extended Filing Deadline
With a timely filed extension (Form 7004)
${calculatedData.extensionDeadline}
`; outputPlaceholder.classList.add('hidden'); outputSection.classList.remove('hidden'); } function switchTab(targetTab) { if (targetTab === 'calculator') { tabCalculator.classList.replace('tab-inactive', 'tab-active'); tabInfo.classList.replace('tab-active', 'tab-inactive'); contentCalculator.classList.remove('hidden'); contentInfo.classList.add('hidden'); } else { tabInfo.classList.replace('tab-inactive', 'tab-active'); tabCalculator.classList.replace('tab-active', 'tab-inactive'); contentInfo.classList.remove('hidden'); contentCalculator.classList.add('hidden'); } } // --- PDF GENERATION --- function generatePDF() { const { jsPDF } = window.jspdf; const doc = new jsPDF(); const entity = calculatedData.entity; const fyEndDate = calculatedData.fyEndDate; const deadline = calculatedData.originalDeadline; const extDeadline = calculatedData.extensionDeadline; doc.setFontSize(18); doc.setTextColor(40); doc.text("Corporate Tax Filing Deadlines", 14, 22); doc.setFontSize(11); doc.setTextColor(100); doc.text(`For: ${entity}`, 14, 32); doc.text(`Based on Fiscal Year Ending: ${fyEndDate}`, 14, 38); const tableColumn = ["Filing Type", "Deadline Date", "Notes"]; const tableRows = [ ["Income Tax Return", deadline, "This is the primary deadline to file and pay taxes due."], ["Extended Income Tax Return", extDeadline, "This is the deadline after filing Form 7004. Note: this is an extension to FILE, not to PAY."], ]; doc.autoTable({ head: [tableColumn], body: tableRows, startY: 50, theme: 'grid', headStyles: { fillColor: [79, 70, 229] }, // Indigo-600 color styles: { font: 'helvetica', halign: 'center' }, columnStyles: { 0: { halign: 'left', cellWidth: 50 }, 1: { halign: 'left', cellWidth: 60 }, 2: { halign: 'left' } } }); doc.save(`Corporate-Tax-Deadlines-for-${entity.replace(/\s+/g, '-')}.pdf`); } // --- EVENT LISTENERS --- if (calculateBtn) { calculateBtn.addEventListener('click', calculateDeadlines); } if (downloadPdfBtn) { downloadPdfBtn.addEventListener('click', generatePDF); } if(monthSelect) { monthSelect.addEventListener('change', defaultDaysForMonth); } if (tabCalculator) { tabCalculator.addEventListener('click', () => switchTab('calculator')); } if (tabInfo) { tabInfo.addEventListener('click', () => switchTab('info')); } // --- RUN ON LOAD --- populateMonths(); defaultDaysForMonth(); });