Business, partnership and estate and trust filers increasingly are targeted by national and international criminal syndicates.
Fraudsters need to dig a little deeper to make tax returns look more legitimate in order to bypass additional security filters that have been put in place in recent years by the IRS and others.
"We've made it harder for criminals to file false returns in volume," Koskinen said.
So he said cyber criminals stockpile names and Social Security numbers that they've collected over the years.
"They try to leverage that data to gather even more personal information," Koskinen said.
"Their goal is to look exactly like the taxpayer."
In the past year, the IRS said there has been a sharp increase in the number of fraudulent business-related filings, including those involving Forms 1120, 1120S and 1041 as well as Schedule K-1.
Beginning next year, more ID theft protection will be used for some business returns. Tax professionals are encouraged to make sure that the name and the Social Security number of the company individual authorized to sign the business return is legitimate. Is the person signing that return really authorized to do so?
The IRS has a new Identity Theft Guide for Business, Partnerships and Estate and Trusts.
Also beginning next year, there will be a new "verification code" box included on all official W-2 forms for the first time. There will be a 16-character code on about 66 million W-2 forms and taxpayers and tax professionals will be urged to enter the code, if the box on the W-2 contains the code.