17 March 2026
To file your FY 2025-26 annual PTRC return after the revised March 15 deadline, you must calculate your standard tax liability and add a flat ₹1,000 late filing fee alongside a 1.25% interest charge for the delayed month. Pay this total online using the MTR-6 challan, carefully separating the tax, interest, and penalty amounts. Then, input these payment details into the Form IIIB Excel utility, validate it to generate a .txt file, and upload it through your MahaGST login.