Which form is used to report donor's tax?

The form used to report donor's tax is Form 709. This form is specifically designed for reporting gifts made during the year that may be subject to federal gift tax. It includes details about the gifts, their values, and any applicable exclusions or deductions, allowing the IRS to assess whether any tax is owed on the gifts.

Form 709 is particularly relevant for individuals who exceed the annual gift tax exclusion amount or make taxable gifts over their lifetime, as it helps track their cumulative lifetime gifts against the lifetime exemption limit. This is why it is the correct choice for reporting donor's tax, serving a distinct purpose compared to the other forms listed.

The other forms serve different functions; for instance, Form 1040 is used for individual income tax returns, Form 990 is for tax-exempt organizations to report their financial information, and Form 1041 is used for estates and trusts to report income. Therefore, these forms are not suitable for reporting donor's tax, as they cater to different aspects of taxation and reporting requirements.