South Korea's tax agency said Monday that it has collected about 6 trillion won ($5.7 billion) less in taxes on-year during the first eight months of this year as the slowing economic recovery undercut corporate and other revenues.

In its briefing to lawmakers ahead of a parliamentary audit session, the National Tax Service (NTS) said that it had collected 129.6 trillion won in national tax during the January-August period, which is 5.9 trillion won less compared with that in the same period a year earlier.

The amount represents 65.1 percent of 199 trillion won that the NTS aims to collect for this year. The ratio is also down from the 70.5 percent tallied during the same period last year.

The NTS attributed the decline to less collection of corporate tax and other indirect tax revenues affected by the toughened economic conditions and slumping private-sector consumption.

The decline comes despite the government's intensifying effort to reduce tax revenue shortfalls in the face of its growing need for fiscal spending on boosting the economy and finance possibly-increasing welfare spending.

The NTS said that it will do its best to make sure that tax revenue shortfalls will be "minimized" this year.

To that end, the tax agency said that it will step up its crackdown on tax evasion by making use of financial data on cash-based transactions that will be provided by the Financial Intelligence Unit (FIU) starting next month.

The government has pursued to revise the country's FIU law to get more access to official financial data. The FIU is an affiliate organization of the Financial Services Commission, the country's financial policymaking body.

Under the revised law, the NTS is allowed to get access to information on cash-based transactions worth 20 million won or larger and other transactions suspected of being used to evade tax payment starting on Nov. 14. (Yonhap News)