Employers registered under EPFO must deposit Provident Fund (PF) contributions and file the Electronic Challan cum Return (ECR) by 15th January 2026 for the preceding month (December 2025). Similarly, ESI contributions and returns under the Employees’ State Insurance scheme are to be completed by this date. Additionally, the TCS Return (Form 27EQ) for the October – December 2025 quarter is due on this day, summarizing tax collected at source for the quarter.