Generally, a resident of a contracting state avoids paying tax on business income earned in the other state unless the income is attributable to a permanent establishment (PE) in the other state. A PE can either be a physical (as in a fixed place of business i.e. office or factory) or through an agency. A dependent agent of the taxpayer with authority to conclude contracts in the name of the principal and which habitually exercises that authority may constitute a PE. However, according to Article 5(4) of the U.S. Model Treat, a PE does not include
The use of facilities or the maintenance of a stock of goods or merchandise in a contracting state for storage, display, or delivery
The maintenance of a stock of goods or merchandise solely for processing by another enterprise,
The maintenance of a fixed place of business for the purpose of purchasing goods or merchandise or collecting information, or
The maintenance of a fixed place of business solely for engaging in any other activity of a preparatory or auxiliary character.
PERSONAL SERVICES INCOME
In newer treaties personal services rendered in a contracting state are taxable only to the extent the income is attributable to a PE. However, under Article 14 of the U.S. Model, if a resident of a contracting state performs dependent personal services in another state, the state where the service was performed has taxing authority if any one of three conditions is satisfied. First, the recipient is present in the state where services are performed for more than 183 days during the taxable year. Second, the payment for services is paid by, or on behalf of a resident of that state. Third, the payment is borne by (i.e., is deducted by) a PE or fixed place of business.
In the absence of a tax treaty, investment income derived from U.S. sources and paid to nonresidents is subject to a 30 percent withholding tax. A tax treaty will usually lower this tax rate between the foreign states. However, where a taxpayer pays tax in both contracting states, the state of residence bears the responsibility of relieving the double taxation. Still, to the extent interest, dividends, or royalty income is attributable to a PE that the recipient maintains, then the income is treated as business profits fully taxable in the state where the PE is situated.
The ability to tax gains of investment property depends on the nature of the property. If gain is derived from the disposition of real property, then the income is subject to tax in the contracting state in which the real property was located. Similarly, gain derived from the sale of personal property (i.e. machinery & equipment) attributable to a PE is taxable in the state where the PE is located. Not surprisingly though, gain realized from the divestment of stocks or securities is usually taxable exclusively in the state of the seller’s residence.