In the first three months of 2017, the Prudential Adviser Helpline team dealt with 5,285 enquiries from advisers, around 1,000 more than the same period last year.
Overall, the service had more than 14,000 enquiries from intermediaries in 2016.
The most common requests for help involved the annual allowance and the lifetime allowance, which accounted for more than 1,000 enquires or nearly 20% of all queries.
Other common topics advisers requested help on include trust planning, appointing trustees, and calculating chargeable events, as well as pensions transfers, tax relief and death benefit options.
Les Cameron, head of technical at Prudential, said: “The large number of enquiries received by the Prudential Adviser Helpline highlights how many advisers are struggling to keep pace with the huge amount of regulatory change that has occurred over the past two years.
“For example, advisers are struggling to understand the complexities of the tapered annual allowance and are turning to our technical experts for help.
“That is not surprising because the rules are extremely complex and take into account all workplace benefits when calculating annual income.”