2. A High Income
The higher the income the higher the chances to be audited by the IRS. Statistics showed that in 2019, those who had an income of more than $200,000 up to $1,000,000 had a very small audit rate, 1% to be more exact.
And those who earned more than $1,000,000 had a 2,4% audit rate in the same year. If you have all the necessary proof and documents then you have nothing to worry about.
Huge amounts of earnings will always be checked by the IRS mainly because they are trying to see if the money you are making are obtained legitimately.