Are you concerned about non-filed tax returns? By law, all Americans are required to file their tax returns, every year, on time; if they meet the defined minimums as outlined each year by the Internal Revenue Service. Whether the IRS sends you a notice of nonfiling or not, it is your duty to file. Whether you receive a form in the mail or not (such as a 1099 or W-2); you are still required to keep proper, adequate records, and file and pay on time.
That's why it's important to take care of non-filed tax returns ASAP. We see countless self-employed people who constantly tell us "Well, I was not on the books for that job or this job; therefore, I do not have to file." or "I didn't receive any Form 1099's, so I didn't make much money last year." Well, the IRS doesn't buy this, nor do we! Think about what you lived on this past year--food, clothing, shelter, vacations, auto payments, etc. . .! Add those amounts up for last year. That is what the IRS will do! If these items add up to, let's say $45,000, then you must have earned at least that much. Your tax return had better show at least that amount of earnings, if you did not live off savings or receive a gift.
The IRS usually only requires the last 6 years of tax returns, maybe up to 10 years, but filing these does not mean that you complied with the laws of the United States if you skipped filing many, many more. The IRS may, out of the goodness of their hearts, allow only the 6 or 10, but you have still violated the law.