You only file a Federal extension for the current name. Don't worry about the prior name.
Also, you do not need to file OK or TN unless you think that you are going to owe tax. Since you said in the old question that the OK company was running based on a loan, there should be no tax liability for that. Similarly with TN. Also, a small balance due is allowed with both states.
Do you want a link for the section where it says that they accept Federal Extensions?
AS for notifying the IRS of the name change, they say that if the EIN was recently assigned and filing liability has yet to be determined, send Business Name Change requests to IRS-Stop 343, Cincinnati, OH 45999.
IF, as I suspect, the EIN was assigned several months ago, then you notify the IRS on the tax form that you file. For corporations, if you are filing a current year return, mark the appropriate name change box of the Form 1120 type you are using:
- Form 1120: Page 1, Line E, Box 3
- Form 1120S: Page 1, Line H, Box 2
If you have already filed your return for the current year, write to us at the address where you filed your return to inform us of the name change. In addition:
- The notification must be signed by a corporate officer.
I said that I would notify them of the name change ASAP. You do so by filing the extension with the new name, followed by the return with the correct name.
It can take the IRS some time to change the name in their files. I have a corporation that is finally in its third year with the new name, and the electronically filed return was finally accepted (it was rejected for name/EIN mismatch in the two prior years). So it can take some patience.