The IRS announced that they will not be accepting e-filed 1040 tax returns until Friday February 12, 2021. This is late even for the IRS. The IRS needs time to implement changes to their systems to incorporate the tax law changes from the latest stimulus law signed by President Trump on December 27, 2020. This delay does not change the due dates of the returns. Your 1040 tax return is still due on April 15 (October 15 if extended)
This delay does not affect businesses. Corporations and partnerships can already e-file.