The General Accounting Office on Thursday released a 26-page report, Tax Shelters: Services Provided by External Auditors (GAO-05-171). Here is the summary:

IRS data available on tax shelter services sometimes predate legislative and regulatory changes reflecting a heightened focus on auditor independence. However, both during this earlier period covered by some of the data and also following the recent changes, auditors were allowed to provide tax services, including tax shelter services, to firms they audited. According to IRS data, 61 Fortune 500 companies obtained tax shelter services from their external auditor during 1998 through 2003 for transactions generally reportable on tax returns sent to IRS. IRS considered some reportable transactions abusive, with tax benefits subject to disallowance under existing law, and other transactions to possibly have some traits of abuse. Estimated multi-year potential tax revenue lost to the federal government from the 61 companies’ auditor-related transactions was about $3.4 billion (about $1.8 billion in categories IRS considered abusive). In 17 companies, at least one officer or director used the company’s auditor to obtain individual tax shelter services. These numbers are imprecise because they have important limitations. These limitations, such as some transactions in IRS’s database without tax shelter providers listed, are fully discussed in this report. Commenting on a draft of this report, IRS said that ongoing changes and recent legislation will enable it to address the data limitations noted.

According to their representatives, all eight case study companies adopted or refined policies or practices in 2002 or 2003 for pre-approving tax services or governing the tax services provided, such as who would provide them. All eight reported using their auditor for tax services during 2000 through 2003. Two told us of obtaining tax shelter services from their auditor, but one of them obtained the services before this period. Six of the eight reported officers or directors obtaining individual tax services from the auditor at some time since 2000, with four disallowing the practice later. None reported officers or directors using the auditor for individual tax shelter services.