All Australian states give people the right to refuse to answer most questions from the police. You do need to provide your name, address, and birthdate; those are required. If you refuse to identify yourself, then you'll need to provide fingerprints. However, past that, you can instead say that you want to speak to a lawyer first and that you refuse to answer questions. It is too easy for police or people around you (including other people in jail, if that's where you end up) to misinterpret your statements as admissions of guilt. Speak with a lawyer first to ensure you don't accidentally incriminate yourself.

You Do Have That Right, for the Most Part

If you're arrested in New South Wales, however, look out for something called a special caution. If the police arrest you and give you a special caution, then your refusal to remain silent can be used to make an adverse inference. In other words, the police can take the silence as a sign of something bad (normally the police can't claim you must be guilty just because you wanted to remain silent). This exception was created in 2013 and has drawn criticisms (e.g., people who don't understand English may want to remain silent because of a language barrier, and this aspect of the law could discriminate against them), but it is still part of the law.

Don't Wait for Them To Tell You That You're Under Arrest

Even if you're not under arrest, you want to be cautious about what you say; the right to silence (except for your name, address, and birthdate) applies to any time that the police question you. Obviously, if you've witnessed a crime, you may want to give the police details. But if they start asking questions that make it sound like you're a potential suspect, you don't want to give them any information that might make them want to arrest you, and again, it's very easy to misinterpret what people say.

Make Your Two Phone Calls

Let's say the police have arrested you, and now you're sitting in the police station, awaiting processing. You're supposed to get two phone calls, one to a lawyer and one to your friends or family members so that they know where you are. Technically, the police have to give you a place to do this where they can't hear you. However, building acoustics and sound insulation can be bad. Never assume that they can't hear you, even if it seems like they've done all they can to ensure they won't hear you. Make your calls and let whoever you're talking to know that you're at the police station. When you speak with a lawyer, you'll have to discuss some details of the charges. But the lawyer will realise that you might not be able to discuss everything then and there.

Even if you know that you're the most innocent person in this case, you'll need legal help if you're arrested for a crime. Call a criminal lawyer to get started on your path to fighting the charges.