GSTR-1 due date for December 2024 is approaching but the GST portal has experienced scheduled downtime starting from 12:00 AM on 9th January 2025, which have been impacting taxpayers who are trying to file their returns. Below is an explanation of the situation, including updates on the extension of GSTR - 1 filing deadline for December 2024. GSTN has requested an extension for GSTR - 1 filing deadline due to technical glitches. The portal is currently under maintenance and expected to be operational by 12:00 noon. Learn more. Here's everything you need to know about GSTR - 1 , including its format, eligibility criteria, and how to file it correctly. GSTR- 1 is a GST return for reporting sales and outward supplies. File monthly or quarterly with ease. Learn who should file and how to file.