Below is information from the IRS regarding the filing requirements for Form 1041 U.S. Income Tax Return for Estates and Trusts along with an explanation of the purpose of the form and when to file the form.
Per IRS Instructions for Form 1041 and Schedules A, B, G, J, and K-1, on page 4:
Who Must File
The fiduciary (or one of the joint fiduciaries) must file Form 1041 for a domestic estate that has:
An estate is a domestic estate if it isn't a foreign estate. A foreign estate is one the income of which is from sources outside the United States that isn't effectively connected with the conduct of a U.S. trade or business and isn't includible in gross income. If you are the fiduciary of a foreign estate, file Form 1040-NR, U.S. Nonresident Alien Income Tax Return, instead of Form 1041.
The fiduciary (or one of the joint fiduciaries) must file Form 1041 for a domestic trust taxable under section 641 that has:
On page 5:
Two or more trusts are treated as one trust if the trusts have substantially the same grantor(s) and substantially the same primary beneficiary(ies) and a principal purpose of such trusts is avoidance of tax. This provision applies only to that portion of the trust that is attributable to contributions to corpus made after March 1, 1984.
A trust is a domestic trust if:
See Regulations section 301.7701-7 for more information on the court and control tests.
Also treated as a domestic trust is a trust (other than a trust treated as wholly owned by the grantor) that:
A trust that isn't a domestic trust is treated as a foreign trust. If you are the trustee of a foreign trust, file Form 1040-NR instead of Form 1041. Also, a foreign trust with a U.S. owner generally must file Form 3520-A, Annual Information Return of Foreign Trust With a U.S. Owner.
If a domestic trust becomes a foreign trust, it is treated under section 684 as having transferred all of its assets to a foreign trust, except to the extent a grantor or another person is treated as the owner of the trust when the trust becomes a foreign trust.
Grantor Type Trusts
If all or any portion of a trust is a grantor type trust, then that trust or portion of a trust must follow the special reporting requirements discussed later, under Special Reporting Instructions. See Grantor Type Trust under Specific Instructions for more details on what makes a trust a grantor type trust.
Note. A trust may be part grantor trust and part “other” type of trust, for example, simple or complex, or electing small business trust (ESBT).
On page 3:
Purpose of Form
The fiduciary of a domestic decedent's estate, trust, or bankruptcy estate uses Form 1041 to report:
On page 8:
When To File
For calendar year estates and trusts, file Form 1041 and Schedule(s) K-1 by April 15, 2021.
For fiscal year estates and trusts, file Form 1041 by the 15th day of the 4th month following the close of the tax year. For example, an estate that has a tax year that ends on June 30, 2021, must file Form 1041 by October 15, 2021. If the due date falls on a Saturday, Sunday, or legal holiday, file on the next business day.
Extension of Time To File
If more time is needed to file the estate or trust return, use Form 7004, Application for Automatic Extension of Time To File Certain Business Income Tax, Information, and Other Returns, to apply for an automatic 5½-month extension of time to file.
To complete Form 7004 Application for Automatic Extension of Time To File Certain Business Income Tax, Information, and Other Returns to file an extension for the 1041 Estate or Trust return in the TaxAct program:
Note that any link in the information above is updated each year automatically and will take you to the most recent version of the document at the time it is accessed.