Amended 1040 Tax Return may now be filed electronically. For the first time, the IRS is now permitting taxpayers to file their amended 1040X tax returns online through commercial tax software. This move certainly offers taxpayers more efficiency with their tax filing and processing but leaves open questions concerning the breadth of the 1040X that may be filed through a commercial vendor. At times, 1040X require expansive explanation and exhibits. A taxpayer may still be, in that situation, be served by paper filing their 1040X. In some circumstances, taxpayer may choose thoroughness over speed.