The latest FOS complaints data has shown Sipps had a higher complaint uphold rate than any other financial product.

For the most recent period – April to June – 66% of Sipps complaints were upheld by the ombudsmen, a higher proportion than payment protection insurance, which stood at 57%, and payday loans at 55%.

The number of enquiries on Sipps received during this quarter - 427 - put it a long way down the list in this respect, compared to other products, despite the high proportion of complaints upheld. There were 328 new cases, with 113 of these going to the ombudsman.

There were far more enquiries on payment protection insurance – over 53,000 – with 43,569 new cases, and for payday loans the figures were 3,963 and 2,729.

Payment protection insurance made up 45% of the overall total complaints for April, May and June.

For personal pensions, there were 965 enquiries, 461 new cases, with an uphold rate of 30%.

For Investment ISAs, there were 381 enquiries, 292 new cases, with an uphold rate of 30%.

For annuities there were 144 enquiries, 128 new cases, with an uphold rate of 13%.