“This is for exactly the same cover with no change in our circumstances apart from being one year older,“ he said.
Travel insurers are predicting 400,000 coronavirus claims, mainly for cancellations. They expect to pay out at least £275m, dwarfing the £62m payments following the Icelandic volcanic ash cloud a decade ago.
While flight and holiday cancellations made by airlines and tour operators are recoverable from the provider, some holidaymakers have had to cancel trips because they fall into high-risk groups.
Mr Hallam said: “In view of the coronavirus pandemic, I was expecting an increase in the cost of travel insurance but certainly not an increase in excess of £900.
“We have been with Aviva for some years and have never made a claim – nor in fact have ever claimed on any travel insurance.”
When Aviva investigated the case, the firm discovered that an error had been made in pricing Mr and Mrs Hallam's 2019 policy.
A spokesperson for the insurer said: “When they renewed their policy in May 2019, the policy was changed from European to Worldwide cover. However, no adjustment was made for the change to cover worldwide trips and we incorrectly provided the customer with the cost of European cover.
“This error meant that last year’s premium was substantially lower than it should have been.
“They also made a change during the year to increase the length of a single trip to 45 days, which would also account for a higher premium at renewal.
“We understand that this year’s price seems much higher than the amount they paid in 2019. Although that price was incorrect, we are offering to reduce this year’s price to the equivalent price for last year: £715.”
Insurers have faced rising travel claims costs in recent years, partly as a result in the slump in sterling following the decision to leave the European Union.
Health care costs have risen sharply, with travel premiums increasing across the industry.
The Aviva spokesperson said: “To help manage price rises, we have been increasing premiums gradually at renewal to bring them in line with the price of an equivalent new policy.”
Aviva has paused the sale of new travel insurance policies as the coronavirus pandemic continues.