A national registration system could be introduced to protect tenants from unscrupulous landlords, it is reported.
Proposals due to be considered by the Government would mean private landlords would have to be registered before being allowed to let residential properties.
Ministers are worried that some rogue landlords are exploiting tenants, The Times reported.
The number of buy-to-let investors has grown over the past decade to about one million in England and Wales.
Anyone letting a residential property, including "accidental" landlords who rent out their homes because they are unable to sell them, would have to pay about £50 for a licence.
They would have to comply with certain standards and those who fail to carry out repairs or who intimidate tenants could be struck off.
It is understood the reforms are to be outlined in a Green Paper within 10 days.
Details of the proposals emerged as a licensing scheme for landlords was launched to help protect consumers from cowboy operators.
The Association of Residential Letting Agents (ARLA) said all of its members would have to be licensed under its scheme and abide by a strict code of practice.
They will also have to hold a professional qualification relating to lettings, undertake continuing professional development and have professional indemnity insurance.
