Yes, but in the case of the Six year Sunstancial Understatement, they have to prove the 25% understatement- the burden of proof is upon them. And, “income” is not deductions. If they are auditing you for deductions, they have 3 years. Your reciepts will avail you naught if they can prove 25% Understatement of Income, as reciepts don’t substanciate income.
Next- Fraud. The IRS also has to prove Fraud, and again the burden of proof is on them, not you, and here again, all the reciepts in the world won’t help if they can prove Fraud. They won’t be checking your more or less legit expenses where reciepts woudl help.
If the IRS can’t get either the 25% Understantment of Income or Fraud to stick, and they have let the 3 year statute go past, then they have barred the entire Statute, and can’t assess or collect a nickel. The IRS gets to decide nothing- either you agree to the “proposed assessment”, or you default, or you lose in Tax Court, in which case the Tax Court decides. Basicly, Civil Fraud is almost never an Audit issue, it gets thrown away in Appeals or in a pre-Court bargain. Except when you plea-bargain down from Criminal Tax fraud.
It is true that during a long audit, the IRS will often ask you to extend the SOL, but in that case, the audit started before the 3 years is up. Quite a bit before, mind you. The IRS likes at least a year remaining on the SOL before they start an audit, preferably two.
My Bro is an Enrolled Agent, and a retired IRS agent. For a year he was District Statute Coord.
His source- is IRS Practice and Procedure by Michael I. Saltzman. Not to mention the IRC, the Regs, and the IRM.
http://www.irs.gov/retirement/article/0,,id=135304,00.html
*The Internal Revenue Service (IRS) makes every effort to examine tax returns as soon as possible after they are filed. To ensure timely tax examinations, Congress has set deadlines for assessing taxes and making refunds or credit of tax. These deadlines are called statute of limitations. Without statute of limitations, a tax return could be examined and tax assessed, refunded, or credited at any time, regardless of when the return was filed.
Statutes of limitations generally limit the time the IRS has to make tax assessments to within three years after a return is due or filed, whichever is later. That particular date is also referred to as the statute expiration date.
*
Or if you don’t trust the IRS:
http://accountantsofficeonline.lebeaucpa.com/Shared/ShowNewsletter.aspx?FirmID=A9565078856D91E19AD01F9CADE8F4F3&NewsletterID=B81C31E4EFA13D69D9CE01E71CF6E802&NSType=1
*Old Tax Returns. The general rule for income tax audits is that the IRS has three years from either the due date of a return or the date the return is actually filed (whichever is later) to initiate an audit. For example, if you filed your 1999 tax return on August 15, 2000, under a four-month automatic extension, the IRS would have until August 15, 2003, to audit that return. If you kept the 1999 return until January 1, 2004, the general limitations period for a tax audit would have expired. Some taxpayers obtain additional 60-day extensions for the filing of their returns, delaying the due date to as late as October 15 of the year following the year to which the return relates. To be on the safe side, you should keep your return until the first day of the year that is five years later than the year to which the return relates. For example, a 2000 return should be kept until January 1, 2005. This rule of thumb ensures that the three-year statute of limitations for the return will have expired by the time you throw the return away.
2. Income Tax Returns Involving a Substantial Understatement of Income. If there is any possibility that you have neglected to declare more than 25 percent of your income on a return, you are playing a different, and much more dangerous, game. The IRS has a six- year statute of limitations (rather than three) to audit such returns. They must prove, of course, that more than 25 percent of the taxpayer’s income was omitted from the return. Still, if this is a possibility, you should keep your return until the first year that is eight years later than the year to which the return relates. For example, 2000 returns should be kept until January 1, 2008, if substantial understatement is a potential problem.
- Income Tax Returns Involving Fraud. If you intentionally file a fraudulent return, there is no statute of limitations for an audit. Therefore, the IRS can come after you at any time. Of course, if a taxpayer is intentionally defrauding the IRS, record keeping is probably not an issue in the first place.
Note this "They must prove, of course, that more than 25 percent of the taxpayer’s income was omitted from the return.
http://articles.chooselaw.com/general/view/Proof-Of-Tax-Fraud.209.html
“For example, the indication standard seems to reflect confusion between the lesser burden of proof imposed on the Commissioner to establish civil fraud and the element of the intent to evade implicit in the statutory term fraud. The quantitative difference in the burden of proof has some effect on the qualitative evidence cited regarding the fraud issue.”
http://www.wtopnews.com/?sid=1335157&nid=114
"*The IRS bears a unique burden of proof in criminal tax cases. It must show not only that someone broke the law, but he or she did so with willful, bad purpose to defraud the government.
A few defendants have won acquittal because the jury thought they sincerely believed they did not have to pay."*