Kallas has been a member of the Estonian Bar Association since 1999 and an attorney-at-law since 2002. Since 26 March 2011 she has been placed on inactive status as a member of the Estonian Bar Association. She has been a partner in law firm Luiga Mody Hääl Borenius and Tark & Co and worked as an executive coach in the Estonian Business School. She is also a member of the European Antitrust Alliance. In November 2018, Kallas published MEP. 4 aastat Euroopa Parlamendis, in which she describes her life and work in Brussels from 2014 to 2018.
In the 2014 elections Kallas ran for the European Parliament and received 21,498 votes. In the European Parliament, Kallas served on the Committee on Industry, Research and Energy and was a substitute for the Committee on the Internal Market and Consumer Protection. She was a vice-chair of the Delegation to the EU–Ukraine Parliamentary Cooperation Committee as well as a member of the Delegation to the Euronest Parliamentary Assembly and Delegation for relations with the United States. In addition to her committee assignments, Kallas was a member of the European Parliament Intergroup on the Digital Agenda and a Vice-Chair of the Youth Intergroup. During her time in Parliament, Kallas worked on the Digital Single Market strategy, energy and consumer policies, as well as on relations with Ukraine. In particular, she stood up for the rights of SMEs, maintaining that borders in the digital world prevent innovative companies from emerging. She is a proponent of innovation and frequently emphasises that regulations cannot and must not hinder the technological revolution. Kallas served as rapporteur for six reports: opinion on the so-called e-Privacy regulation, Civil law rules on robotics and on the Annual report on EU Competition Policy, and on Delivering a New Deal for Energy Consumers, legislation on Custom infringements and sanctions and the own-initiatative report on the Digital Single Market. During her time in the Parliament she was also nominated as a European Young Leader.
Return to national politics
On 13 December 2017, the leader of the Reform Party Hanno Pevkur announced that he would no longer run for party leadership in January 2018 and suggested that Kallas should run instead. After considering the offer, Kallas announced on 15 December that she would accept the invitation to run in the leadership election. On 3 March 2019, the Reform Party, led by Kallas, won the general election with about 29% of the vote, the ruling Estonian Centre Party taking 23%.
