The Goods and Services Tax (GST) Network is currently evaluating a potential one-day extension for the filing of GSTR-3B returns for the March 2026 tax period due to reported technical issues on its portal. Many chartered accountants and tax professionals have expressed concerns about the portal's functionality, especially as the April 20 deadline approaches. Despite these issues, the government has not yet issued a formal extension, meaning the original deadline remains in effect.

If taxpayers miss the April 20 deadline, there are significant consequences. An 18% annual interest on the net tax liability will accrue for each day of delay, alongside a late fee of ₹50 per day for normal returns, capped at ₹10,000. For nil returns, the late fee is ₹20 per day, capped at ₹500. Delayed filing can also hinder a business's ability to claim input tax credit and disrupt vendor relationships.

Taxpayers are advised to keep their records reconciled and avoid filing during peak portal loading times. While technical issues may be grounds for relief, taxpayers must document these issues to justify any delays. Automatic relief is not guaranteed, and official government notifications are necessary for any extensions or waivers of penalties.