The deadline for filing the GSTR-3B return for the March 2026 tax period is set for April 20, 2026, despite significant complaints from chartered accountants and advocates regarding the functionality of the GST portal. Many users, including Gujarat-based Chartered Accountant Deep Koradia, reported severe slowdowns and login issues on the filing day, making it difficult to submit returns. Failure to meet the deadline can lead to penalties, including a late fee of ₹50 per day, or ₹20 for those with no tax liability. Additionally, interest on unpaid dues is charged at an annual rate of 18%. The GST Network (GSTN) has acknowledged the feedback regarding the portal's issues and is working on solutions, particularly concerning the mandatory confirmation process for tax liabilities that has been criticized for being overly burdensome. Taxpayers are advised to follow interim procedures suggested by GSTN until the issues are resolved.