ARLA believes that a high proportion of these agents are not being regulated properly or meeting the required standards for lettings agents.
Ian Potter, operations manager of ARLA, said this raised serious questions about their professionalism and he believed it could damage the industry’s reputation.
"To make the transition from an estate agent to a lettings agent, they need to have studied more than a hundred different pieces of legislation, and pass minimum competency tests to ensure their ability to advise clients to the required standards," he said.
"This is a big concern for landlords and consumers. Those consulting an agent need to be absolutely sure they are getting the best advice possible to ensure the safety of their investment."
ARLA is launching a licensing scheme at the House of Commons on 5 May this year to further strengthen its commitment to best practice and professionalism in the lettings industry.
On average, ARLA members said that around four estate agents in their local area had moved into the rental market, with some stating that as many as 10 agents were now operating in this sector.
Potter said: "My advice to those looking to rent a property would be to go through a regulated lettings agent to be absolutely sure you’re covering yourself from either a cowboy agent or any insurance liabilities."
Peter Bolton King, Chief Executive of the National Association of Estate Agents (NAEA) said: "We would always advise consumers to use qualified and regulated agents, because that way they can have confidence in their transaction.
"I can understand why estate agents, or unregulated start-up agents, have appeared in the lettings market after a tough year, but they could get themselves and their clients into trouble if they aren’t completely aware of the relevant legislation.
"An appropriate licensing scheme across the property industry would put an end to situations such as this, and the worries that accompany them, in a stroke."
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