Entry into force of tax treaty determines when it applies to taxes on income and capital in each state. The Convention enters into force upon the exchange of instruments of ratification. Its provisions apply in Spain to taxes on income or on capital for any taxable year beginning on or after 1 January of the calendar year following entry into force; in India, it applies to income arising in any taxable year beginning on or after 1 April of the calendar year following entry into force and to capital held on the last day of any taxable year beginning on or after that 1 April.