The Association of British Insurers (ABI) said its members received 229,932 phone calls between 7 and 10 April from customers interested in finding out more about their pension options.
This marked a 214% increase in average call volumes and worked out at an average of 57,483 calls per day, it said.
Calls reached a peak on Tuesday, the first working day defined contribution savers were granted unfettered access to their pension pots by the government under recent reforms.
ABI insurers also received a total of 10,000 written and email requests each day that week, double the usual amount, it said.
A recent survey from website RetireEasy suggested the majority of well-off pre-retirees were clued in to the changes despite experiencing poor contact from their provider so far.
The site found more than half of its client base – people with average private pension assets of £146,000 – had still not been contacted by their pension provider in light of pensions freedom, but 68% were aware of the changes and potential charges.
Retirement policy manager Rob Yuille said: “Unsurprisingly many customers, recognising the importance of the reforms, are contacting their pension provider to understand how the changes may affect them.
“Insurers have taken steps to meet this demand, and will continue to explain to customers their options, and encourage them to speak to the free, impartial Pension Wise service before taking any action.”