Rents in England and Wales rose by 0.1% in January to an average of £712, according to LSL Property Services.
This is the first time rents have increased in January since the firm's records began in 2008 and the first monthly rise since October.
In the past year, rents were up 4.3%. This works out at an extra £30 for the average household to pay.
Tenants in London are still paying the most each month, with rents at an average of £1,032 - 6.3% higher than a year ago - while those in the East Midlands have the cheapest monthly rents at £547.
In the West Midlands and South West monthly rental costs rose fastest in January, rising by 1.8% and 1.5% respectively. The biggest decline was in the East of England and Wales where they fell 1.7% and 1.5% respectively.
But despite the rise, rental arrears - late or unpaid rents - remained flat in January compared with December. However, the 10.7% figure is still above the annual average of 10.2%.
"The rental market burst back into life unseasonably early in January, with tenants on the move trying to take advantage of what is usually a quieter period for the rental market," says David Newnes, director of LSL.
"The depth of the underlying demand sustained a higher level of competition for rental property during the Christmas period, preventing more severe falls in rents than we would normally see during this period," he adds.