After months of large scale non-compliance in filing of the summary return (GSTR-3B) by taxpayers under Goods and Services Tax (GST), the tax department has started sending reminder notices to such assessees. Some of the notices issued for the first three months of this year has given taxpayers three days to comply, or else the department would assess the liability based on information available with them. The notices are in line with government\u2019s stated approach of employing enforcement actions gradually as the system stabilises. The tax department has also asked assessees to explain the mismatch of details filed in GSTR-3B and GSTR-1 (outward supply). Besides, central board of indirect taxes and customs (CBIC) has launched a year-long exercise to verify transitional credit claims made by top 50,000 assessees. \u201cYou are requested to furnish the said return with three days, failing which the tax liability will be assessed under GST Act, 2017, based on the relevant material available with this office,\u201d one of the electronically generated notices reviewed by FE said. It added that no further communication will be issued for assessing the liability and an assessee will be liable to pay interest and penalty along with applicable tax. \u201cIf returns aren\u2019t filed even after notices, the department can undertake tax liability assessment on the basis of sales made to a particular assessee. We could also use the past tax record and other data points to arrive at the liability,\u201d a tax official said. While the GSTR-3B compliance has steadily improved since July last year, it\u2019s still not satisfactory to the tax department. Only around 55% eligible taxpayers were filing monthly returns by the deadline during July-October.