Research by Ocean Finance found that 60% of tenants reported that their landlord increased their rent on their current property at the end of a fixed period. The average increase was £84 a month or £1,008 a year.
More than one in 10 (13%) were also hit with fees to extend their existing tenancies, the average fee to extend an existing tenancy agreement totalling £117.
The study showed that more than half of tenants stay in the same house for five years or more, which could see them paying almost £600 in letting agents’ fees to continue renting their home.
According to figures from the Office for National Statistics, prices on private rentals increased by 2.1% in the year to March 2015.
Ocean spokesperson Gareth Shilton said: “The buy-to-let market is booming at the moment, driven partly by the London market, although there are strong hotspots across the country.
“As demand for rented properties continues to outstrip supply, and many people struggle to get on to the housing ladder, landlords are in a strong position to continue to increase rents each time a tenancy agreement ends.
“On top of rental increases, tenants are facing rip-off fees from letting agents, not just to take new tenancy agreements, but also to roll-on an existing tenancy for another six or 12 months.”