The government expects an over 20 per cent increase in its overall revenue collection in Q3 of the current fiscal, a senior Central Board of Direct Taxes (CBDT) official said.

"I am hoping that in Q3, we can see an increase of about 22-23 per cent in the overall revenue collection. This will, of course, mean an increase of about 25 per cent in the corporate tax collection," CBDT's Member (Revenue) Durgesh Shankar told PTI here.

However, much would depend on the self-assessment tax, Shankar said, adding that filing of returns by companies is due now.

"The returns are due now. There will be a self-assessment tax paid by people who were conservative last year. If such tax collection this time round is higher, then it will impact our overall Q3 collection," Shankar said.

Self-assessment tax is the amount payable by the taxpayer if his tax liability as assessed by him is more than the advance tax paid by him.

"Q3 (collection) is very important for us," he said. Shankar said that there is a definite pattern to tax collection in which the Q1 collection is normally around 15 per cent and Q2 25 per cent, whereas Q3 and Q4 are at 30 per cent each.

Quarter 2 has seen an overall revenue growth of 17 per cent, which is very significant. The impressive thing is that corporate tax has grown by 19 per cent and non-corporate tax by 14 per cent, Shankar said.

"Our expectations were that corporate tax would go up by 23 per cent but the non-corporate tax would peak at 12 per cent. This shows that there is a subtle shift in the engine of the revenue growth," he said.

The tax authorities are also hopeful of a higher TDS collection at 38 per cent this fiscal as against 36.5 per cent last year on account of certain initiatives taken by the government to enhance the collection.

"The data (on TDS) which is coming in this year is much cleaner than last year. But it is still not perfect. Last year, our collection from TDS was 36.5 per cent and I am hopeful that this year it will be around 38 per cent," Shankar said.

He, however, said that Mumbai needed to pull-up its socks and aim for a higher TDS collection.

"Mumbai is doing well. There are certain areas where they need to pull-up their socks such as TDS. They need to enlarge the scope," he said.