What is mailing address for filing Form 4768?

To file Form 4768, you should send it to the appropriate address based on whether you are filing for an estate that is located in the United States or outside of it. For estates in the U.S., the mailing address is: Internal Revenue Service, P.O. Box 593, Indianapolis, IN 46206-0593. For estates located outside the U.S., you should mail it to: Internal Revenue Service, P.O. Box 2099, Ben Franklin Station, Washington, DC 20013-2099. Always check the most current IRS instructions for any updates or changes.