Sometimes trader may use older software with earlier GST rates, and there can be errors in calculation due to change in GST rates. However, during the online filing of GST, the form has updated rates mentioned. Wrong rates applied can lead to greater tax payment as GST rates have reduced significantly for most goods. GST form filing is more frequent than ITR, and some forms have to be filed monthly. It’s best to get to know the exact applicable rates at earliest and correct the same in software.