The Internal Revenue Service and the Department of the Treasury recently issued the Notice of Proposed Rulemaking Guidance Regarding Foreign Base Company Sales Income, which concerns an amendment to Treasury regulations affecting controlled foreign corporations (CFCs). In addition, the IRS recently released a Private Letter Ruling on the tax implications for CFCs of disposing of emissions allowances. This article considers the impact of these on the subpart F income of CFCs, and contrasts US treatment with that in Australia.