Citizens Advice has recorded an increase in the number of problems with letting agents reported by tenants, with a sharp rise coming from the 17-24 age group.
The organisation has reported advising on 6,500 problems with agents between July 2015 and June this year, up 14% from the 5,700 problems reported two years ago.
In the last year, it says it has been made aware of 810 problems among 17-24 year-olds, compared to 360 between July 2013 and June 2014.
The charity has subsequently added its support to calls for a ban on letting agency fees charged to tenants.
It says agency fees have increased considerably in recent years, by as much as 60% in some cases.
Citizens Advice says landlords should be charged agency fees, as they are in a better position to 'shop around' and choose a letting agency they want to work with.
To coincide with Citizens Advice's report, the housing association Genesis surveyed 17 London letting agents and online agencies.
It found that the average tenant would pay £436 in up-front fees, which covers reference, guarantor checks, inventory and contract fees.
The study also looked at 'end of tenancy' fees and found the average agency to be charging £130, covering an inventory check-out and future landlord references.
“Private renters shop around for properties, not for letting agents. Landlords are better able to choose agencies based on performance and cost and it should therefore be landlords paying letting agent fees, not tenants picking up these rising costs," says Gillian Guy, cheif executive of Citizens Advice.
“It is concerning that younger renters are among the most likely to report problems with a letting agent, when many will end up using letting agents to find somewhere to live at university."
Last week, data from Upad revealed that 60% of 500 tenants would rather a rent cap than a ban on letting agency fees.