TurboTax will let you e-file as of sometime January 4. They (and other tax software companies) allow that to garner marketshare. Even if you e-file then, your return will just sit on a server— going no place—-until the IRS begins to accept/reject e-files later in January. While your e-file sits on that server for a few weeks, you will be powerless to fix it if you discover---as many people do -- that you made a mistake, left out income, etc. etc. etc.