Are all double tax treaties signed by countries/jurisdictions effective?

Poland has signed 90 bilateral double taxation agreements. A list of agreements and their contents is available on the website of the Ministry of Finance.

However, Polish entities wishing to take advantage of the privileges of such an agreement (for example, in order to apply a lower rate or exemption) should verify whether the given agreement has been ratified by both countries despite its signature.

For example, a new agreement between Poland and the United States (the Agreement of 13 February 2013) has only been ratified by Poland. The ratification took place in August 2013, i.e. 6 months after it was signed. However, until today the agreement has not been ratified by the USA. In the USA the ratification procedure involves three stages. In the first stage, the signed bilateral agreement is sent to the Senate Committee on Foreign Relations in order to prepare appropriate recommendations and send it to the Senate. Then the U.S. Senate approves the international agreement by a two-thirds majority and sends it to the President for signature. The agreement is ratified by the signature of the President of the USA.

Therefore, until the ratification of the double tax treaty agreement of February 13, 2013 by the USA, Polish entities in their relations with the USA apply the provisions of the current agreement between Poland and the USA of October 8, 1974.