Data from Your Move's England and Wales Rental Tracker shows that the number of tenants in arrears increased for the fourth consecutive month in April.
The agency found that 9.4% of all its tenancies were in arrears last month, up from 9.1% in March, 8.6% in February and 8.4% in January.
It says, however, that the proportion of tenants behind on their rent remains well below the recent all-time highs of 14.6% recorded in February 2010 and 13.7% recorded in July last year.
As for average yields, Your Move reports that the East Midlands was the only region to record an increase between March and April - up to 4.3% from 4%.
In the North West and East of England, meanwhile, average yields suffered, dropping to 4.8% and 3.7% respectively.
The average yield across England and Wales remained steady at 4.4% during April.
The monthly study also looks at average rents and found that the strongest performing region was the South West where typical rental values have increased by 3% in the last 12 months and 0.3% on a monthly basis.
With an average rent of £654 and growth of 2.9% over the last year, the East Midlands was the next best performing region.
Wales and the North East are the only two regions to have recorded negative growth over the last year, dropping by 2.1% and 1.6% respectively in the year to April.
At the other end of the scale, London continues to have the most expensive rents in the country.
In April 2018 the average rent in the capital was £1,275, although prices have only risen by 0.1% in the last year.