The agreement was signed in London on 6 December 1921 by representatives of the British government (who was Prime Minister David Lloyd George, head of the British delegates) and by representatives of the Irish Republic, including Michael Collins and Arthur Griffith. The Irish representatives had a plenipotentiary status (negotiators entitled to sign a contract unrelated to their superiors) acting on behalf of the Irish Republic, although the British government refused to recognize that status. As stipulated in the terms of the agreement, the agreement was approved by “a meeting” of members elected for the presidency of the Lower House of Southern Ireland and [separately] by the British Parliament. In fact, the de facto Legislative Assembly of the Republic first debated the treaty; The members then continued with the “meeting.” Although the treaty was narrowly adopted, the split led to the Irish civil war, won by the pro-treaty party. No agreement had been reached on a similar immigration policy at the time, but a year after Ireland`s justice minister called the lifting of immigration controls between the two islands “the business of the British themselves,” the British began for the first time to mention the CTA in the legislation.  The content of the agreement is provided for by applicable immigration legislation.   (ii) acknowledge that it is up to the inhabitants of the island of Ireland alone to exercise, by mutual agreement between the two parties and without external hindrance, their right to self-determination on the basis of united and simultaneous consent, north and south, if that is their wish, by accepting that this right be acquired and exercised with the agreement and approval of a majority of the people of Northern Ireland; The agreement obliges the two governments to continue their cooperation through the CTA, to align their lists of visa-free countries, to develop an electronic border management system,to participate in the joint use of data to combat the “abuses” of the CTA and to work towards the establishment of a “fully common visa for short-term stays”.    Common Travel Space (CTA); The Irish territory of Comhlimistéar Taistil is an open border territory that includes the United Kingdom, Ireland, the Isle of Man and the Channel Islands. British overseas territories are not included. On the basis of agreements that are not legally binding, the internal borders of the CTA, if any, are subject to minimal controls and can normally be overtaken by British and Irish citizens whose identity documents are minimal, with some exceptions.   The continuation of the CTA implies cooperation between the British and Irish immigration authorities. The agreement, which is the culmination of more than two years of work between the two governments, means that the rights of citizens of both countries will be protected after Brexit, while ensuring that Ireland continues to meet its obligations under EU law. The agreement came into force on 31 January 2020, when the UK effectively left the European Union.
Like its previous predecessors, the 2011 agreement is non-binding, with the eighth clause stating that the agreement “is not intended to create legally binding obligations or confer a right, right or benefits on a private or public person or party.”  In the meantime, de Valera had been appointed President of the Republic on 26 August, in order to be able to accredit plenipotentiary parties for negotiations, as is the case between sovereign states.  On 14 September, all speakers unanimously stated that plenipotentiaries would be sent to represent the Sovereign Republic of Ireland and accepted Valeras` appointments without against notice, although some argued that de Valera himself should attend the conference.  There is no passport control for Irish and British citizens travelling between the two countries.