The volume of Financial Ombudsman Service complaints about self-invested personal pensions and small self-administered schemes increased by 34 per cent in 2016/17.
In its annual review for the 2016/17 financial year, published today, the FOS says the number of Sipp and SSAS complaints went from 1,174 complaints to 1,574.
Overall there was a 15 per cent rise in complaints about pensions from 4,495 in 2015/16 to 5,160 in 2016/17.
As well as Sipp complaints increasing, complaints about income drawdown also rose by 8 per, while complaints about personal pension plans increased by 20 per cent.
The number of annuity complaints dropped by 3 per cent from 763 to 743.
The FOS data shows 1,602 complaints against advisers were resolved, with 36 per cent upheld.
The FOS resolved 242 Sipp-related complaints against advisers, of which 64 per cent were upheld.
It also resolved 181 complaints laid against advisers about portfolio management with 43 per cent upheld.
AJ Bell platform technical head Mike Morrison says a permitted investments list would help avoid some of the issues related to Sipps.
Morrison says: “Only investments on the permitted list would be covered by the Financial Services Compensation Scheme and it would have to be made clear to investors that anything off that list is not covered.
“The list would include regulated investments for which there is some consumer protection in place already and it would not have to be static, with new regulated categories added in future.”
Advisers accounted for 0.5 per cent of the total 321,283 new complaints received by the FOS over the last year.
The FOS received 161 new complaints about advisers where the event being complained about happened more than 15 years ago. This represented 7 per cent of the total number of adviser complaints.