Tax Administration Simplification Act

The Tax Administration Simplification Act streamlines tax filing for small businesses and individual taxpayers. It extends the deadline for S corporations to make election filings to the due date of their tax return (including extensions), and shifts individual estimated tax payment due dates from June 15 and September 15 to July 15 and October 15. The bill also extends the "mailbox rule" to electronic filings and payments, treating them as filed on the transmission date if sent by the due date, even if received later. These changes apply to tax years beginning after the bill's enactment, with Treasury required to issue implementing regulations within one year.