More than 3,500 Covid-19 related complaints have been sent to the financial services watchdog.
The Financial Ombudsman Service (FOS) called on some financial firms “to do more” to treat customers fairly after the barrage of complaints.
It said almost a quarter of complaints are from consumers who have had travel plans disrupted and had travel insurance claims declined by their insurer.
About 200 complaints were also made to banks from consumers who want their money refunded by their credit provider for cancelled holidays, sport fixtures and concerts, under Section 75 of the Consumer Credit Act 1974.
The FOS said the figures also showed that is has received more complaints from small businesses this year than it received in the whole of the last financial year.
This increase was largely driven by complaints about business interruption insurance and Covid-19 related loan schemes, it said.
It said there was also a jump in complaints related to weddings, as people made insurance claims over cancelled ceremonies and venues.
Caroline Wayman, chief ombudsman and chief executive of the Financial Ombudsman Service, said: “Covid-19 has had a huge impact on virtually all elements of our lives, including our finances.
“Since measures to control the virus in the UK were put in place, we’ve been hearing from people who aren’t happy with how their financial provider has treated them.
“We also know that financial businesses themselves have been impacted in their ability to process claims and complaints, and we’ve seen that many have adapted well.
“However, some financial businesses must continue to do more to ensure they are treating their customers fairly.”