Figures from the Central Statistics Office show that the number of people signing on the Live Register increased in December following falls in the previous three months.
The seasonally adjusted figure was 444,000, up 5,200 from November.
The unexpected jump in the numbers of new claimants more than wipes out the drop of 4,200 on the Live Register in November. It is the first monthly increase since August.
The headline figure, which does not take account of seasonal factors, jumped by just over 12,000 to 437,079. Overall that number has grown by 13,500 people in the past year.
The Live Register itself includes some part-time and seasonal workers and does not measure unemployment. But the unemployment rate implied by the jump in December is 13.4% - up from 13.2% in November.
