Petplan is offering an "insurance amnesty" to enable policyholders with a 12-month claim limit with other insurers to transfer to its Cover for Life policy.
The amnesty, which will run until December 31, was developed after a Petplan survey showed that 38% of its claims were for conditions that lasted a year or longer.
Petplan spokesman Richard Barrett said many pet owners bought cheaper policies that only paid out for the first year of an illness or injury.
"After that, they just don't want to know," he said. "You may have saved a few pounds in the short term but could have ended up costing yourself a fortune later on."