[citation needed] In World War II, as part of Operation Fish, securities from the United Kingdom were secretly moved to the Sun Life Building for safekeeping.

The new government also promised a referendum on Quebec sovereignty, injecting instability into the Montreal business community.

[7] On January 6, 1978, Sun Life became the first large company to leave Quebec post-election, announcing that it would move its head office to rented space in Toronto, Ontario.

[7][8][9] Officially, Sun Life said it was motivated by the political instability and economic uncertainty of Quebec's future, but skeptics said it was the company's unwillingness to comply with the requirements of Bill 101.

[9] In a reaction the next day, the province's finance minister Jacques Parizeau called Sun Life "one of the worst exporters of Quebec capital",[10] and threatened to freeze some $400 million CAD in assets.

[10][11] In 1979, the company acquired a property at University Avenue and King Street in downtown Toronto and constructed a new office complex, the Sun Life Centre, which was completed in 1984.

The PQ government was quick to label Sun Life "bad corporate citizens" and claimed that if "they had only warned us, we could have worked something out.

[14] In 2008, Sun Life sold its 37% interest in CI Financial Income Fund to Scotiabank.

Sun Life had originally acquired a significant ownership interest in the firm by selling its Canadian mutual fund subsidiaries to CI Financial in 2002.

[18] In 2012, Sun Life celebrated the 100th anniversary of its Canadian head office building, located on King Street, right on the border of the Cities of Kitchener and Waterloo.

[19] Sun Life U.S. has the sixth-largest group benefits business in the United States and serves more than 60,000 employers in small, medium and large workplaces.

[20] In 2018, Sun Life U.S. was named one of the Top Places to Work in Massachusetts for 2018 by The Boston Globe.

[16] Sun Life operates in eight Asian markets - China, Hong Kong, Malaysia, Singapore, Indonesia, Vietnam, India, and Philippines.

Sun Life grew to become the biggest foreign insurer in China until the Second World War when it shut down operations.

[32] For some years, it had taken over the MPF schemes from a number of other competitors in 2010s due to its strong performance of the Hong Kong equity fund.

[35] The Insurance Regulatory and Development Authority (IRDA) granted registration in principle to Birla Sun Life.

Hence, on its 129th anniversary, headed by CEO and Benedict Sison, it remained the top life insurance company for 13 consecutive years with P55.79 billion in Total Premium Income.

[47] Sun Life committed to having 25% of under-represented minorities and gender parity at senior leader level by 2025.