(SINGAPORE) Even as their numbers continue to swell, Singapore's top earners' average tax bill hasn't shrunk - despite the slide in tax rates here over the years.

The taxman's Year of Assessment 2007 (YA 2007) - for income earned in calendar year 2006 - saw a near-30 per cent surge in the number of people in the million-dollar club to 2,751, figures from the Inland Revenue Authority of Singapore (IRAS) show.

These big earners earned $5.64 billion in total - about $2.05 million on average - and paid a total of over $900 million in income tax for the year.

That works out to a tax bill of some $327,200 per millionaire - up from the previous year's average of some $321,000, and not much lower than the $332,000 average five years ago.

This is despite the fact that Singapore's income tax rates have been cut in recent years, with the personal rate somewhat lagging the corporate rate. For YA 2007, the top rate for corporate and personal income tax was 20 per cent, though the corporate rate has since fallen to 18 per cent with effect from YA 2008.

The IRAS data, published in its latest 2007/08 annual report, also shows starkly the tax profile here - the 2,751 top earners amounted to a mere 0.3 per cent of the total number of taxpayers in YA 2007, but accounted for almost 20 per cent of total personal tax assessed for the year.

In all, a total of 856,833 taxpayers were assessed income tax of some $4.58 billion for YA 2007.

With 2006 having been a robust year for the economy - GDP growth was 8.2 per cent - IRAS had a bumper collection in its 2007/08 financial year that ran from April 2007 to March 2008: Total tax revenue grew 27 per cent to $29.1 billion, with increased takings in all types of taxes.

Corporate income tax added $9.3 billion to the coffers, up about 9 per cent from the previous year.

Individual income tax collected in the FY 2007 - as opposed to the tax assessed for YA2007 - amounted to $4.55 billion, a good 21.5 per cent increase.

And with the two percentage-point hike in the Goods and Services Tax (GST) rate to 7 per cent in July 2007, GST revenue grew sharply from about $4 billion in the previous year to $6.2 billion.

Stamp duty collection also surged, from just over $2 billion in FY 2006 to $3.7 billion in FY 2007.

Meanwhile, the cost per dollar of tax collected continued to slide - to 0.77 cent, from 0.83 cent in the previous year.

However, the tax collection cost per taxpayer has gone in the other direction - from $54 in FY 2003 to $78 in FY 2007.

Tax arrears amounted to 1.1 per cent of tax contributions for FY 2007, down from 1.9 per cent in previous year.

And $154 million in penalties were collected - in 11,286 cases uncovered - from those who tried to evade paying taxes.

IRAS expects all GST traders to get on to the e-filing bangwagon by next month - the deadline, anyway, for them to join other businesses in tax-filing electronically.

This article was first published in The Business Times on September 9, 2008.