The actress and her husband both smiled when the penalty was delivered by magistrate Bernadette Callaghan.

They hugged each other tightly as the court room was cleared.

Ms Callaghan said she accepted Heard had made a genuine mistake.

"I accept she did not set out to deliberately deceive the Australian authorities, I also accept she is not a person who thinks she is above the law," Ms Callaghan said.

The actress will have to pay a $1000 fine if she does not remain of good behaviour for the next month.

And here’s the video played to the court – posted on Facebook by Barnaby Joyce:

2.33pm: We're back and it sounds like we could be here for a while, with magistrate Bernadette Callaghan saying, "Ms Heard, normally I would deal with this with you standing but I have a bit to say."

Amber Heard has taken her seat again. Johnny Depp is again sitting beside her, after being accosted by a couple of autograph hunters as he entered the court.

Amber Heard has pleaded guilty to falsifying her immigration card.

The illegal importation charges have been dropped.

The prosecution conceded Pistol and Boo didn't pose a major threat to Australia's biosecurity but the case is designed to deter "offenders more dangerous than this one".

The defence contended the couple believed their pets' paperwork was in order.

Amber Heard accepts responsibility for the mistake and has voluntarily returned to Australia for the case because she wanted to offer a public apology, according to the defence.

Johnny Depp and Amber Heard shot a video on the Gold Coast yesterday, in which she expresses her remorse for the situation and both talk about the importance of Australian biosecurity.

The court was adjourned until 2.30pm when the magistrate is expected to deliver the sentence.

12.36pm: Heard's defence lawyer has just compared Pistol and Boo to an apple and a chocolate bar. I think. Huh? I'm confused.

Anyway, essentially what he is trying to say, I believe, is that all of us are guilty at some point of not declaring things on our immigration arrival cards, like an apple or a chocolate bar.

But Pistol and Boo were not chocolate bars or apples. Glad we got that cleared up.

"This is not like bringing in an apple or a chocolate bar, it's the sort of thing that ordinarily was going to be noticed," he said.

"The only reason it was not noticed, let's be frank it was because it was a private flight."

12.18pm: We are nearing the end of the defence case.

We're now at the part where the defence tells the magistrate what an honourable person the defendant is and how she works with charities and deaf people and the LGBTI community and please don't give her a conviction because she may not be able to travel to other countries and work.

"Ms Heard travels often with the dogs she never would travel without the relevant documents and was prepared to accept no for an answer when the relevant documents were not prepared," her lawyer said

"There is no forethought or planning here - there was nothing to gain, no commercial aspect to it.

"This offence without being accompanied by more serious charges is rare."

12.11pm: Heard's defence lawyer said despite the misunderstanding surrounding her immigration card, she accepts responsibility for the mistake she made.

"She has returned voluntarily to Australia, her and her husband have not reason to be here other than to be this court today," he said,

"She did not need to be here but she has chosen to be here and subject herself to the attention which will be obvious to your honour.

"It's obviously a very unusual matter and this is a very unusual step

"Ms Heard wanted to offer a public apology."

12:10pm: The court has just been shown a video shot by Johnny Depp and Amber Heard on the Gold Coast yesterday, in which she expresses her remorse for the situation and both talk about the importance of Australian biosecurity.

It was pretty awful. You would never guess these two make their living in front of a camera.

But no doubt it will be snapped up for an in-flight public service announcement.

11:54am: Heard's defence lawyer said she did not deliberately falsify her arrival card because she genuinely thought quarantine clearance had been taken care of by her husband's staff.

"Everything is handled by his people," she said in her statement.

"This is usually handed over to Johnny's staff, along with my passport and visa."

She said during a conversation with her husband in their Los Angeles kitchen prior to their trip to Australia last April, he assured her Pistol and Boo could travel with them.

Heard also assumed that because there were separate arrival documents obtained for the dogs' arrival, based on her travel experience, she did not think she had to declare them on her arrival card.

"She positively believed the relevant documentation had been provided to the relevant authorities," her lawyer said.

11:35am: On the couple's first trip to Australia the dogs did not go because the documentation was not ready, the defence has told the court.

Depp's personal assistant indicated the dogs would be good to travel in April, so the couple assumed all the relevant clearances had been made.

"We're not usually involved in the details of those travel arrangements," Depp said in his statement.

11:30am: It's the defence's turn now.

Vet examinations performed on the dogs revealed the terriers to be healthy and Heard provided an unsworn statement to the department last year about what happened. 

She offered to plead in October to the falsification of the immigration card if the two illegal importation charges were dropped.

The Department of Agriculture rejected the offer, which they agreed to before the court today.

11:25am: The Commonwealth prosecutor is taking about the importance of Australian quarantine laws and has conceded, contrary to Barnaby Joyce's opinion, Pistol and Boo did not pose an enormous threat to the country's bio security.

"This is to deter offenders, yes offenders more dangerous than this one," he said of the laws.

Sounds like the public gallery is also going to be treated to seeing the video Heard made, expressing her remorse.

The director remains unknown.

11:18am: And we're back.

The facts are being read by the Commonwealth prosecutor.

This is the stuff we already know. Private jet, two dogs, false arrival card, etc.

Pistol and Boo were here for nearly three weeks before they were discovered.

11:03am: Johnny Depp and Amber Heard are back in the courtroom to learn her fate.

The pair are again sitting next to each other in swivel chairs behind her lawyers, chatting quietly to each other as we wait for the magistrate to enter.

10:52am: Court is due to resume in about 10 minutes.

Here is a highlights package from the morning session.

Hollywood actors Johnny Depp and Amber Heard arrived shortly before 9am

The stars were greeted by a media pack and a few fans

There was no pre-court press conference

Heard pleaded guilty to falsifying her immigration card.

The illegal importation charges have been dropped.

10:07am: It's live cross central outside the Southport Magistrates Court at the moment.

Depp and Heard remain inside, where they are expected to stay until court reconvenes at 11am.

With two charges dropped by the Department of Agriculture against Heard, and just one remaining, the big question now is, has anyone told Barnaby Joyce.

There's been no sign of the Deputy PM and though he was not expected at court, we though he might have at least done a drive-by.

9:43am: Depp and Heard, both dressed in black, are sitting behind their lawyers.

The case has been adjourned until 11am in order for the magistrate to read a "substantial volume" of material about the case.

Depp has been scribbling notes on a post-it note as prosecution and defence lawyers have been addressing the judge, with his wife's handbag slung over the back of his chair.

At one point, he dropped the post-it pad, giving his wife a supportive wink as he lent over to pick it up.

9:27am: Court is in session.

Ms Heard and her husband are sitting in the front left corner.

She is about to formally plead guilty.

She has pleaded guilty only to the charge of falsifying her immigration card. The illegal importation charges have been dropped.

9:26am: The Department of Agriculture and Amber Heard have reached a resolution over their long running battle over the illegal importations of her two terriers.

A three-hour hearing has been allocated in court 10 at Southport Magistrates Court, in which she will plead guilty to three bio security charges.

This excuses her husband, Johnny Depp, from giving evidence at what had been scheduled for a four day contested hearing.