A "hybrid mismatch" arises if double non - taxation results from the exploitation of differences in the tax treatment of an entity or financial instrument under the laws of 2 or more countries.

There is double non - taxation if a deductible payment is not included in a tax base (this is called a deduction/non - inclusion mismatch), or if a payment gives rise to 2 deductions (this is called a deduction/deduction mismatch). Disallowing a deduction, or including an amount in assessable income, "neutralises" this tax advantage.