<ul><li><a href=https://www.riigiteataja.ee/en/eli/ee/518032022002/consolide/current target=_blank>Electronic Communications Act(Elektroonilise side seadus, RT I 2004 87 593,  adopted on 8 December 2004, last amended on 17 January 2020, article 89 (4))</a></li><li><a href=https://www.riigiteataja.ee/akt/116062011015 target=_blank>Regulation on number portability by Ministry of Economic Affairs and Communications(Nõuded numbri liikuvuse tagamiseks sideettevõtja vahetamisel, RT I, 16.06.2011, 15, adopted on 1 September 2011, last amended on 3 January 2019, articles 3 and 6 (3))</a></li></ul>