The number of income-tax payers in the country has nearly doubled from 1.73 crore in 1998-99 to 3.37 crore in 2007-08, as per the tax department.
In 1998-99, the effective income-tax payers base stood at 1.73 crore with their overall contribution to the exchequer at about Rs 46,600 crore.

The taxpayer base for 2007-08 had swelled up to 3.37 crore with direct tax contribution to the exchequer at Rs 3,12,000 crore.
Also the share of corporate taxes to the total direct taxes had gone up from about 50per cent in 1998-99 to 60 per cent in 2007-08, as Indian companies made robust profits aided by the strong economic growth during 2004-05 to 2007-08.

The year 2007-08 was a landmark year for another reason “ it was the first time ever that the direct tax collections accounted for more than 50 per cent of the Centre s revenue kitty.

Factors that brought about the deepening as well as widening of taxpayer base.
Initiatives such as computerisation of the department (since 2001) has to some extent contributed to the deepening although there are issues like need for faster processing of returns that the department was still grappling with.

Also, tax information network (TIN) and mandatory e-filing of returns eased compliance with income-tax law and procedures.