The IRS released Notice 2020-18 making the extension of the filing deadline official. Any person or entity (corporations, partnerships, LLCs, etc.) that has a return due April 15, 2020 or a tax payment due on that date has an automatic extension for both filing returns and paying those payments until July 15, 2020. Extensions are not required.
Notice 2020-17 put dollar limitations on the extensions ($1 million for individuals and $10 million for corporations), the new notice supersedes Notice 2020-17 and removes those dollar limitations.
Note that only income tax returns and payments are deferred; all other types of returns and payments must be paid on time to avoid penalties and interest, including payroll tax and excise tax returns.
The IRS has released Information Release 2020-57 that provides details about the procedure to claim the credits enacted as part of the Families First Coronavirus Response Act (the Act, PL 116-127, 3/18/20).
Click this link to view a copy of the explanation of the Information Release (with our annotations) published this morning by Thompson Reuters.