Want the biggest pay rise? Then become a 'boomerang' worker and go back to your old employer

• Workers going back to their former employer are winning pay rises of up to 28%, new research found.
• Visier, a software company, analyzed 3 million employee records at 129 global companies.

While "quiet quitting" is making headlines, some workers are doing something even more unusual: returning to workplaces they left only months earlier.

New research by Visier, a software company, found "boomerang" employees who rejoin their former employer scored pay rises of up to 28% in the first four months of this year.

That compares with an average rise of just 10% for workers changing jobs, according to data from think-tank the Pew Research Center.

Visier analyzed three million employee records at 129 global companies. Andrea Derler of Visier told CNBC that boomerang workers can use their knowledge of a company as well as added external experience as leverage for higher salaries.

According to Visier, about a third of external hires between January 2019 to April 2022 were boomerang workers, who returned 13 months after leaving on average. It also found that 40% of them obtained management roles above their previous level.

Boomerangs initially resigned in search of new horizons or because they could not see opportunities to progress with that employer, according to Visier's research.

A year into the "Great Resignation", positions are going unfilled and critical projects have been delayed due to a lack of workers, which means it could be the right time to ask for a raise rather than resign.

Derler told CNBC that companies need to better reward and engage high performers if they wanted to retain talent by offering raises and promotions at least every two years.

Working relationships are one of the main reasons why people go back to a former employer, according to Visier data.

"It sounds like an HR skill, but the onboarding skills of a manager in the first year can't be overstated enough," Derler told CNBC.

Managers should take time in the first year to engage new hires in a company's culture and social networks, she added.