In a YouGov poll of 5,379 adults commissioned by the housing charity, 23% of those polled said they had been charged unfair fees by letting agents in England.

Roughly 14% of people surveyed said they had been unfairly charged ‘administration fees’, followed by credit checks at 10% and 8% said they had been overcharged for renewing a contract.

An investigation by Shelter revealed renters had been peppered by overcharging, including £150 each year for repeat credit checks which cost less than £25 and £100 for property viewings.

The investigation also uncovered admissions from ex-lettings staff they had fabricated fees to increase their profits and charged some renters up to £540 for non-refundable ‘administration’ fees.

Agents also admitted double-charging both landlords and tenants for the same service, said Shelter.

The survey revealed the reason most people felt unfairly charged was that the fees charged were out of proportion to the cost or amount of work done by the letting agent.

Kay Boycott, director of campaigns, policy and communications at Shelter, said: “It’s scandalous that some letting agents are creaming off huge profits from the boom in private renting by charging both tenants and landlords fees that are totally out of proportion to the service they provide.”

Shelter is calling on renters and landlords to visit its website to share their experiences to join the fight against wrongful fees.

Shelter’s investigations have also found landlords hit by bad practice from letting agents.

Abdul Motin, a landlord from London, said: “A letting agent who was supposed to be renting out my home has ripped me off for £9,000, and we’re now struggling to meet the mortgage. The letting agents falsified the tenants’ references, withheld the rent and deposit from me, and have now dissolved their company. This is the only property I own and I’ll never rent it out again. This has been a living nightmare for me and my family.”

Angelique Atkinson, a renter from Hampshire, paid £540 in administration costs when she rented a home with her partner. She said: “We didn’t receive any justification for these extortionate fees, and ended up having to pay nearly £3,000 upfront, making a huge dent in our finances. I have nowhere I can complain to and be taken seriously. We can’t afford to buy our own home; renting is so expensive that it seems impossible to save for a deposit. The rental market is a horrible place right now.”