Tax harmonization is generally understood as a process of adjusting tax systems of different jurisdictions in the pursuit of a common policy objective. Tax harmonization involves the removal of tax distortions affecting commodity and factor movements in order to bring about a more efficient allocation of resources within an integrated market. Tax harmonization may serve alternative goals, such as equity or stabilization. It also can be subsumed, along with public expenditure harmonization, under the broader concept of fiscal harmonization. Narrowly defined, tax harmonization guided by this policy goal implies — under simplifying assumptions about other policy instruments and economic structure — convergence toward a more uniform effective tax burden on commodities or on factors of production. Convergence may be attained through the alignment of one or several elements that enter the determination of effective tax rates: the statutory tax rate and tax base, and enforcement practices. Perhaps the most widely accepted argument for harmonization involves convergence in the definition of product value or income for tax purposes. Such tax base harmonization would contribute to transparency for economic decision-making and, thus, to improved efficiency in resource allocation. In particular, a common income tax base for multinational companies operating in different jurisdictions would be instrumental not only in enhancing efficiency, but also in preventing overlaps or gaps in tax claims by different countries. Tax harmonization is an important part of the fiscal integration process. Fiscal integration is the process by which a group of countries agree on taking measures that lead to a higher level of fiscal convergence, the ultimate goal being the formation of a fiscal union. Tax harmonization doesn't automatically lead to the formation of a fiscal union, the second part involving much larger scale project that includes fiscal transfers, a fully harmonized legislation and maybe some supervising institutions, beside a long-run agreement. Starting from the definition given to the fiscal integration process, we can easily say that tax harmonization is the process by which a heterogeneous group of countries, federal states or even local governments agree on setting a minimum and maximum level of their tax rates, including also a higher degree of harmonization of tax legislation, in order to attract foreign investors and to encourage local development and investments.