Islington has become the latest council to introduce a limited landlord licensing scheme.
The local authority will regulate properties on the busy Holloway and Caledonian Roads, which contain some 600 properties, many of which are divided into small flats.
Under new plans, Islington Council will require all landlords to apply for a licence for properties that are occupied by three or more people, when properties are split into two or more households.
This is a more stringent requirement than current rules, which only require registration for properties with more than five people and more than three storeys.
The proposals also include fines of up to £20,000 for landlords who fail to register when required.
Islington is also planning the launch of a new local authority-backed letting agent, which will offer to guarantee rents when they meet affordability criteria.
Labour Councillor James Murray said: “More and more people in Islington are renting privately and we want to help make sure they get decent homes that they can afford.
“Our proposal for extra landlord licensing along the whole of Holloway Road and Caledonian Road comes after widespread evidence of poor management, including serious issues around electrical safety, fire alarms, and landlords letting out tiny ‘shoebox’ flats.
“Alongside this, our new council-run lettings agency will offer a better deal for private tenants. There will be no fees for tenants and a management service from the council.”