Self-styled Islamic preacher Junaid Thorne has been released on bail after being sentenced to nine months' jail for travelling under a false name.

The 26-year-old was charged with using a false name to book an airline ticket from Perth to Sydney and using that ticket in December last year.

Thorne said he used the fake name to avoid detection by law enforcement authorities.

He and two other co-accused, 22-year old Perth-based Omer Issak and 19-year old Mostafa Shiddiquzzaman, pleaded guilty to the charges earlier this year.

Shiddiquzzuman was sentenced on Monday to four months in custody.

Issak was given a community-based order in a Perth court earlier this year.

Shiddiquzzaman used his own credit card, with the frequent flyer points going to Thorne.

Thorne is originally from Perth and had recently moved to Sydney.

The court had heard earlier that while Issak made no admission he was trying to avoid the scrutiny of police, both Thorne and Shiddiquzzaman had said in their pre-sentencing reports that they were trying to elude authorities.

In Monday's hearing, Magistrate Mark Buscombe said "regrettably we're living at the height of security concerns".

He said it was only appropriate that the offenders be placed in full-time custody "as there was some planning involved and both understood they were subject to the scrutiny of security services".

Thorne's actions stupid and rash: lawyer

Thorne's wife Basma Cherkaoui was present at the hearing, with Magistrate Buscombe telling the court she had three children, and the family lives in Sydney's south west, along with Shiddiquzzaman.

Thorne's lawyer, Paul Bodisco, had described his client's actions as "stupid and rash" but "was not sophisticated offending".

He said Thorne did not understand using a fake name to travel was an offence at the time of the booking.

When he was told, Thorne tried to change the booking but did not because of the extra cost, Mr Bodisco said.

"He understands now that shortcuts have consequences," he said.

"He thought he was avoiding scrutiny [by changing his name on the ticket]. Instead all he's done is invite scrutiny from the authorities."

In its sentencing submission, the Crown argued it was important for the security of the Commonwealth that people travelling could be accurately identified.

Thorne, an Australian citizen, had been investigated by the Federal Government for his apparent support for a militant group in Perth.

He was deported from Saudi Arabia two years ago, where he lived for 14 years with his family, for protesting against his brother's imprisonment.

His brother was in prison for terrorism offences and has since been released.

Thorne had also voiced his support for the Charlie Hebdo massacre in Paris earlier this year, along with other posts on social media supporting the so-called terrorist group Islamic State for the fall of Mosul.

He also said teenager Numan Haider - who was shot dead outside a Melbourne police station last year - was one of his followers.

Thorne's lawyers are set to appeal his sentence in August.