我觉得这笔interest 应该没有connected with a U.S. trade or business，所以说应该填schedule NEC，看了下instruction，税率30%。
Withholding of tax at the source.
Tax must be withheld at the source on income not effectively connected with a U.S. trade or business that is paid to nonresident aliens. The withholding is generally at a 30% rate. The tax must be withheld by the person who pays the income. For details, see Pub. 519, Pub. 515, and section 1441 and its regulations.
根据这个irs作为person who pays the income会withhold 30%。
Line 9a—Taxable interest. Report on line 9a all of your taxable interest income from assets effectively
connected with a U.S. trade or business.
If you received interest not effectively connected with a U.S. trade or business, report it on Schedule NEC, page 4, unless it is tax exempt under a treaty and the withholding agent did not withhold tax on the payment. If the interest is tax exempt under a treaty, include the tax-exempt amount on line 22 and complete item L of Schedule OI on page 5.
If the interest is tax exempt under a treaty but the withholding agent withheld tax, report the interest on
Schedule NEC, line 2. Use column d and show 0% for the appropriate rate of tax.
刚刚看了一眼treaty，好像dividend和interest都只at most subject to 10% tax。
However, such dividends may also be taxed in the Contracting State of which the company paying the
dividends is a resident, and according to the laws of that Contracting State, but if the recipient is the beneficial owner of the dividends the tax so charged shall not exceed 10 percent of the gross amount of the dividends.
However, such interest may also be taxed in the contracting State in which it arises and according to the laws of that Contracting State, but if the recipient is the beneficial owner of the interest, the tax so charged shall not exceed 10 percent of the gross amount of the interest.
If the nonresident alien individual uses Form 1040NR to report his income, then such nontaxable interest income shall not be reported anywhere on Form 1040NR except in response to question L on page 5 of Form 1040NR.