The average rent for a buy to let property grew by 2.1% in the year to September, an index has revealed.
The figures from HomeLet show that the average rent now being paid is £927 every month.
For landlords in London, rents rose by 1.9% over the same period with the average rent now standing at £1,593.
The index highlights that rents have increased in 11 of the 12 regions being monitored and only rental properties in the south east of England saw a fall in rents - they dropped by 0.1%.
Highest annual rental increase seen by landlords
However, the highest annual rental increase was seen by landlords in Northern Ireland where rents grew by 4.3%, in the West Midlands they rose by 3.9% and in the East Midlands by 3.7%.
The chief executive of HomeLet, Martin Totty, said that the figures point to the re-emergence of rents rising once again.
He explained: “It would be a surprise if landlords who are seeing costs increase not passing these onto tenants to preserve their returns.
“Landlords are facing higher costs from taxation changes on BTL mortgages, new regulations and the prospect of an interest rate rise in the near term.”
Potential fallout for landlords
Mr Totty added that there's also the potential fallout for landlords with the government's plan to ban letting agent fees.
Landlords have also received welcome news from estate agents haart who say that the number of tenants rose by 3.4% in September across the UK.
This led to rents rising 0.6% during the month and the average rent now being paid is £1,268.
Also, research from real estate firm Knight Frank points to increasing rental demand from tenants in central London which is now outstripping supply.
Rents in central London fell
In their prime central London rental index, the firm says that rents there fell by 0.1% in the three months to September. The average rent in the capital is now 3% lower, year-on-year.
A spokesman for Knight Frank said: “While the availability of properties to let has become muted, the demand is rising and it's boosting rental values.
“The number of prospective tenants were registered in the first eight months of 2017 grew by 19.6% and viewing levels are 25% higher than last year.”
He added that the recent tax changes on buy to let properties have not led to declining levels of rental stock entering the market and there's little sign that landlords are planning to sell-off their portfolios.