Each financial year on 15 April, is the due date for the filing of your income tax. Your tax return cannot be audited after 3 years from its original date of filing. In case you file it before the due date, 15 April, the three years will be counted from 15 April of the year it was due. You should be aware of the IRS tax laws so that you are aware of what is in store for you each time you expect an audit.
Some of the exceptions to this rule include:
If the income details is 25% or more on your return, the audit is prolonged to six years.
In case of filing fraudulent return, there is no imposition of a time limit on an audit. Tax fraud is meant to deceive the IRS, as is when using an invalid Social Security number. A mistake done negligently not with intention, isn't fraud. The IRS determines what fraud is, and it almost never audits returns after 3years even in case of evident fraud.
The statute of limitations or the time audit period starts only if and when you file a return. If you have not filed taxes and not received audits from the IRS you have most likely escaped their audit process.
Audit notices are sent by first class mail and never emailed or done via the telephone, between the period of 12 and 18 months after your tax return is filed. If there has been no notification within 18 months, you are not likely to be audited.
The rules in the Internal Revenue Manual urge auditors to finish audits within 28 months. Of course, the IRS has legally 36 months. The extra time is to allow them to process claims on your behalf, plus there are usually delays due to backlogs, transfers, and other postponements.