The Internal Revenue Service increased its audits of S corporations and partnerships by around 25 percent in fiscal 2007, reflecting its increased attention to businesses that pass their income through to individuals.

The IRS audited 17,681 S corporations and 12,195 partnerships. Audits of mid-market corporations were up 6 percent to 4,473. Business audits in general increased 14 percent to 59,515. Audits of large corporations dropped slightly to 9,644.

The number of individual returns audited increased 7 percent to 1.38 million, the highest number since 1998. Audits of individuals with $100,000 or more in income were up nearly 14 percent. The IRS audited 31,382 individuals with income of $1 million or more, an 84 percent increase from 2006.

The IRS filed 3.8 million levies and obtained almost 700,000 tax liens, also an increase from a year earlier.