The U.S. parent of the taxpayer rented equipment to the taxpayer for use by the taxpayer in its Canadian operations. Although the U.S. parent was considered to be carrying on a business in Canada, i.e., providing various administrative, supervisory and other services to the taxpayer at cost, the rents received by it could not reasonably be attributed to any part of the business which it carried on in Canada. The rental agreements were made in the United States, rentals started when the equipment left California, delivery of the equipment to the taxpayer took place in the United States, and payment was received in the United States. Accordingly, as the rental payments were revenues of a business carried on instead in the U.S., the withholding tax exemption in Reg. 805 was not available.