Workers on a zero-hours contract as their man job stood at 801,000 at the end of 2015, which is up by 104,000 from the year before the Office for National Statistics (ONS) said.
Since the ONS began monitoring the number of zero-hours contracts, this is the highest report and means that 2.5% of the employed UK workforce is on this type of contract.
In November, there were around 1.7 million contracts that did not guarantee a minimum number of working hours, which means that workers may have had more than one zero-hours contract.
Seasonal factors could have affected the previous estimate but the ONS said they should not be directly compared. Workers on zero-hours contracts were likely to be young people, part-time workers and students in full-time education opposed to other people in employment.
The ONS has also said that those on the contract, on average, worked 26 hours a week but a third of those wanted to work longer in their current job, rather than more hours in a different job. Only 10% of people in other types of jobs wanted more hours.