The private medical insurance (PMI) market's two biggest players have seen a rise in the number of complaints escalated to the Financial Ombudsman Service (FOS).
Grievances relating to some of the protection market's biggest providers also jumped, although these totals are harder to attribute due to the way the data is presented.
However, despite these increases the sectors account for a very small volume of total complaints dealt with by FOS.
According to figures provided by the regulator for individual firms, both Bupa and Axa PPP saw complaint levels rise with Bupa seeing 87 complaints between last July and December escalated to the FOS (compared to 64 in January to June).
Axa PPP had 60 complaints handled by FOS during the same period, compared to 58 in the previous six months.
Groupama also saw a rise in its total caseload, from 128 to 160, but this includes the general insurance business.
In the protection sector isolating figures is harder as data for these products are split into categories with other products.
However, Royal London (which includes Bright Grey and Scottish Provident), saw its total number of cases sent to FOS more than double (to 441 from 208), while Ageas (359 from 250), Aviva (521 from 408), Legal & General (308 from 210) and Zurich (260 from 177) also saw significant increases.
Aviva responded to the figures by saying it had over 14 million policyholders and that those who did refer matters to the Ombudsman represented 0.01% of its UK customers.
"Occasionally things are not as the customer expected and complaints help us understand where we can improve and what our customers' opinions are on our products and services," the insurer said.
"Although we aim for no complaints, the ones we get represent less than 0.2% of our UK customers.
"When our customers come to us with a concern, our first priority is to discuss the matter and resolve it, where possible within 10 days.
"Where a customer still has concerns, we advise them of their right to approach the Financial Ombudsman Service with their complaint," it added.
LV= with 43 complaints (down from 47) and Canada Life (67 up from 52) rounded out the major IFA market businesses published.
The data published by FOS covers businesses where the regulator received at least 30 new cases and resolved at least 30 cases in the six month period.
Overall, the major banking groups provided the greatest volume of complaints, with Barclays leading the way with 11524 grievances, 6975 due to the payment protection insurance (PPI) saga.
