FTAdviser recently reported (25 September) that the value of fines issued by TPR had more than tripled in a year, reaching £42m in 2017/18.
Ricky Chan, director and financial planner at IFS Wealth and Pensions, said: "If the adviser firm has the responsibility to re-asses the business' re-enrolment then they could be liable if the employer is fined and makes a claim.
"But this is unlikely as the employer has ultimate responsibility to ensure they re-asses their eligible employees, any fines that TPP were to hand down would apply to employer.
"Large firms are likely to have functions in place but smaller businesses may struggle or may not be aware of their role."
He added: "I'm not sure how much of a big issue this will be, because people who opt out of the workplace pension may have left the company within the three years."