Under section 1446(a), a partnership (foreign or domestic) that has income effectively connected with a U.S. trade or business (or income treated as effectively connected) must pay a withholding tax on the effectively connected taxable income (ECTI) that is allocable to its foreign partners. In most cases, a partnership determines if a partner is a foreign partner and the partner’s tax classification based on the withholding certificate provided by the partner. The tax rate for such withholding varies depending on whether the foreign partner is a corporation, ’n which case the rate is the highest rate of tax specified in IRC 11(b). In case of foreign partners that are not corporations, the rate is the highest rate of tax specified in IRC 1.
The withholding tax rate for effectively connected income (ECI) allocable to non-corporate foreign partners is 37%, and 21% for corporate foreign partners.
Partnership may be required to file Forms 8804, 8805, and 8813 to pay and report section 1446 withholding tax based on effectively connected taxable income (ECTI) allocable to foreign partners (as defined in section 1446(e)).
The partnership, or a withholding agent for the partnership, must pay the withholding tax. The partnership that must pay the withholding tax but fails to do so may be liable for the payment of the tax and any penalties and interest.