Of the 20 local authorities that responded to a freedom of information request from the trade body, more than half, or 53 per cent, did not prosecute a single letting agent in the four-year period from 2014/15 to 2017/18.
Around a third prosecuted three or fewer, with the NLA flagging up Liverpool City Council as the outlier, having prosecuted 13 agents.
In contrast, 13 of the authorities questioned have introduced a landlord licensing scheme.
The NLA argued that while letting agents play a “vital role” for landlords, some are guilty of transgressions that could lead to the landlord receiving enormous fines or even criminal charges.
Richard Lambert, chief executive officer of the NLA, said that he was “shocked” that so few letting agents have been prosecuted, and called on local authorities to “take much firmer action” on rogue agents.
He added: “While many local authorities have introduced licensing schemes to crack down on rogue landlords, they seem to be allowing letting agents to get off scot-free. This must stop.”
Consumer champions Which? accused letting agents of breaking consumer law earlier this year, after a mystery shopping exercise found many agents demanding deposits before allowing tenants to view the contracts.
A new enforcement team, aimed at ensuring agents follow the new rules on banning certain fees, has also been launched by Trading Standards.