The IRS requires that taxpayers include every dollar earned on their returns, even if a 1099 is not received. The company you worked for is required to issue a Form 1099 to each non-employee that earned over $600 in a given year. They are supposed to mail these by Jan. 31 of each year. The company also sends a copy to the IRS. Then, the IRS matches 1099 information they receive to your tax return.