Article 49 EC must be interpreted as precluding legislation of a Member State, such as the legislation at issue in the main proceedings, under which payments made by a resident taxpayer to a non-resident company for supplies or services are not to be regarded as deductible business expenses where the non-resident company is not subject, in the Member State of establishment, to tax on income or is subject, as regards the relevant income, to a tax regime w
hich is appreciably more advantageous than the applicable regime in the former Member State, unless the taxpayer proves
that such payments ...[+++]relate to genuine and proper transactions and do not exceed the normal limits, whereas, under the general rule, such payments are to be regarded as deductible business expenses if they are necessary for acquiring or retaining taxable income and if the taxpayer demonstrates the authenticity and amount of those expenses.