Landlords in Oxford now need to show they are complying with safety standards, as a new scheme comes into force.
The 'selective licensing' scheme, which begins on Thursday 1 September, means that all private rented homes in the city need a licence.
The policy, which previously only affected houses in multiple occupation, will be in force for five years.
Licensing requires private landlords to show that they are complying with the law by meeting safety and management standards, being a 'fit and proper person' and meeting council waste storage and disposal requirements.
The introduction of the policy comes after the government approved the scheme in April.
It means Oxford is the only council area outside London requiring a licence for all private rented homes.
How much will the licence cost?
A five year licence costs £480.
Landlords and agents who make a complete application by 30 November will qualify for an early bird discounted rate of £400.
There is also a discounted fee of £280 for accredited landlords.
The City Council said the new licensing policy in private rented homes will help to protect tenants and crack down on rogue landlords.
Councillor Linda Smith, Cabinet Member for Housing said: "Oxford needs decent homes and the launch of selective licensing will help make that a reality for private tenants who have - too often - had to put up with substandard and frankly dangerous conditions.
"Selective licensing will protect private tenants by driving up standards and cracking down on the rogue landlords who make their lives a misery. The majority of responsible landlords and agents who already do a good job have nothing to fear, as a licence means tenants will have confidence in their ability to provide safe, well maintained and well managed homes."