The act contains a range of law changes, including increased prison terms for serious crimes such as certain terrorism offences and internet trolling.
It has also changed the law so anyone who kills a police or prison officer in the line of duty faces spending the rest of their life behind bars.
The act will also end the automatic release of those jailed for child rape and serious terrorism offences half-way through their prison sentence.
New offences coming into force include revenge pornography, causing serious injury by driving while disqualified, and remaining unlawfully at large following a recall from licence.
The act also reduces the burden of the cost of courts on taxpayers by making criminals pay towards the cost of their court cases. It also brings in reforms that balance the judicial review system so justice is done but unmerited, costly and time-wasting applications no longer stifle progress.
Justice Secretary Chris Grayling said:
Crime has fallen, serious offenders are going to prison for longer and now we have changed the law to deliver tougher and swifter justice for victims and the public.
As well as bringing in a range of vital new offences and other important legal changes our reforms are strengthening sentencing powers to provide better protection for our communities.
The act received Royal Assent on 12 February and commencement orders have now been made.
Measures in the act coming into force include:
measures that ensure that all child rapists and terrorists serving custodial sentences will only be released before the end of their prison term if the independent Parole Board decides they no longer represent a risk to the public
a new criminal offence of revenge porn has been created, meaning that those who share private, sexual images of someone without consent and with the intent to cause distress will now face up to 2 years in prison
banning cautions for criminals convicted of serious offences and, for less serious offences, stopping repeat cautions for anyone who commits the same or similar offence more than once in a 2-year period. Serious offenders will instead face being brought before the courts where they could face a prison sentence
making possession of extreme pornography that shows images depicting rape illegal
increasing the maximum penalty to 2 years in prison for online trolls who send abusive messages or material
four new criminal offences of juror misconduct. These are researching details of a case (including online research), sharing details of the research with other jurors, disclosing details of juror deliberation and engaging in other prohibited conduct
imposing a new fee at the point of conviction to make criminals contribute towards the costs of running the courts system
creating a new offence of causing serious injury by driving while disqualified, carrying a maximum penalty of 4 years in prison, and increasing the maximum prison sentence for causing death by disqualified driving to 10 years. We have also changed the law to make sure that driving bans are extended so they continue to apply after an offender has come out of prison
increasing the maximum penalty for prisoners who fail to return from a period of temporary release from 6 months to 2 years in prison
creating a new offence of remaining unlawfully at large following a recall from licence. The new offence will punish those who deliberately, and wilfully, seek to avoid serving the rest of their sentence in custody and carries a maximum penalty of 2 years in prison
supporting economic growth through measures to speed up the Judicial Review process and reduce the number of meritless claims clogging the system
tackling insurance fraud by new measures that ban law firms from offering inducements, such as iPads or cash, to potential clients and courts will be required to dismiss personal injury cases entirely where the claimant has been found to be fundamentally dishonest, unless doing so would cause substantial injustice