"If this threshold is reached, then the site shows a message asking the taxpayer to wait for his turn in a few minutes," GSTN said in a statement.
GSTN claimed that more than 11.52 lakh GSTR3B (October) returns were filed on Tuesday out of which about 1.82 lakh returns were filed in a peak hour.
It said that over 8.14 lakh returns were filed on Monday and over 9.23 lakh GSTR 3B returns were filed by 4.00 pm on Wednesday.
Referring to complaints, GSTN said that it could have been possible that some filers may have momentarily experienced being logged out at the load threshold of 1.5 lakh returns load at a particular point of time or some difficulty due to any local issue at the taxpayer filers' end.
"But the GST return filing system has been working as expected and coherently and a total of more than 55.79 lakh returns were filed by 4.00 pm today," the statement read.
The GST filing service provider requested taxpayers not to wait till the last three days to file their returns due to huge rush which is seen during these days.