A 25-year-old Darwin man has been sentenced to nine years' jail, after pleading guilty to child sex offences and fraud charges.

Scott Quinn pleaded guilty to the offences, which happened in Darwin and Palmerston between December 2011 and August last year.

Quinn admitted to having sex with four girls between the age of 12 and 15, and attempting to procure four others for sex.

He also pleaded guilty to six fraud charges, including booking hotel rooms so he could have sex with some of his victims, using the credit card details of customers from his workplace.

Quinn faces a non-parole period of six years and six months, less 12 months already served.

During the trial, the court heard Quinn befriended the girls on Facebook and met them later.

The prosecution told the court that Quinn sent explicit pictures of himself to the girls.

Quinn's lawyer told the court that while children needed to be protected from such behaviour, his client had never forced the girls to have sex with him.

In sentencing in the Northern Territory Supreme Court today, Chief Justice Trevor Riley said Quinn had a moderate chance of rehabilitation, so long as he used his time in prison well.

Quinn will serve most of his sentence in protective custody.