You do not have to give any details when arrested or at the police station.
If you don’t give a name and address at the police station, it may delay your release, but they can only hold you for 24 hours (except for very serious offences) and must then charge or release you, even if they don’t have your details.
If you do decide to give your details, you only need to give your name, address, and date of birth.
Never give your details before being ‘booked in’ at the custody desk, as people are often arrested as an intelligence-gathering exercise.
In mass arrest situations, all arrestees should consider not giving details until charged with a crime. The mass arrest is often done for the purpose of getting people’s details – there is unlikely to be evidence that you have committed a crime. If you decide not to give your details, it makes it easier for others to make the same choice.
You are only legally obliged to give your details if and when you appear in court.
Police will attempt to verify any details you give, perhaps by looking you up on the police computer or sending local police around to the address you have given to confirm you live there. If they can’t verify they may not release you on bail.