Fifteen landlords who failed to comply with a Welsh Government scheme designed to regulate home rentals have been prosecuted, Rent Smart Wales has said.
The scheme was started two years ago to help tackle bad landlords.
A further 185 people have been issued with fixed penalty notices.
However Rent Smart Wales said of the estimated 90,000 landlords in Wales, 87,000 had now registered with the scheme.
A number of people have been prosecuted at Cardiff Magistrates court for breaches of the Housing (Wales) Act 2014.
Kowswer Choudhury of Princes Avenue, Cardiff, was fined £3,600 for failing to submit a licence application after initially registering on the scheme.
Vale of Glamorgan landlord Anthony Thomas pleaded guilty to managing his 10 rental properties without a licence and must pay a total of £665. Meanwhile Lee Jones of Albion Road, Port Talbot admitted failing to register or become licensed and must pay a total of £430.
Lynda Thorne, Cardiff cabinet member for housing, said: “Self-managing landlords in Wales must realise that registering with Rent Smart Wales is not enough to comply with the law.
“They are also required to pass training and submit a licence application.”
Over 800 landlords have registered in the past two months, although it does mean there are still around 3,000 who are operating illegally.
Rent Smart Wales said it now had over 177,000 properties signed up to the scheme.
It also announced that from 1 April 2018, all new properties coming on to the rental market or those renewing tenancies would have to have a rating of E or above on an energy performance certificate.