ViSOR is the Violent and Sex Offender Register, it is used as a Management Tool by UK Law Enforcement, National Offender Management Service (including the Prison Service) along with a wide range of other agencies, to manage, Registerable Sexual Offenders, Other Sexual Offenders, Violent Offenders,  Registerable Terrorist Offenders, Dangerous Offenders, Violent Offenders and Potentially Dangerous Persons as part of Multi-Agency Public Protection Arrangements (MAPPA). ViSOR is managed by the National Crime Agency.

Typically persons on the database will have relevant serious convictions or cautions, but a person can be included if they are considered potentially dangerous and have no formal criminal record at all.

Prior to a a change in the law in 2012 following on from a decision in the Supreme, sexual offenders who had been sentenced to longer than 30 months detention had to remain on the Sex Offenders Register for life.

In 2012 the law changed so that in the case of youths after 8 years, and adults after 15 years, an offender could apply to the police (providing they are not subject to Sexual Offences Prevention Order) to be removed from the register. If the police refuse this application, it can be appealed to the Magistrates court.

When making a decision the police must consider the risk of sexual harm posed by the qualifying offender, and the effect a continuation would have on the offender. The police must take into consideration a number of factors, including the following:

• the seriousness of the offence in relation to which the qualifying relevant offender became subject to the indefinite notification requirements;
• the period of time which has elapsed since the qualifying relevant offender committed the offence (or other offences);
• the age of the qualifying offender at the qualifying date or further qualifying date
• the age of the qualifying  offender at the time the relevant offence was committed
• the age of any person who was a victim of any such offence (where applicable) and the difference in age between the victim and the qualifying relevant offender at the time the offence was committed
• any assessment of the risk posed by the qualifying relevant offender which has been made by a responsible body under the arrangements for managing and assessing risk established under section 325 of the Criminal Justice Act 2003
• any submission or evidence from a victim of the offence giving rise to the indefinite notification requirements
• any convictions or findings made by a court (including by a court in Scotland, Northern Ireland or countries outside the United Kingdom) in respect of the qualifying  offender for certain types of offences
• any caution which the qualifying relevant offender has received for an offence (including for an offence in Northern Ireland or countries outside the United Kingdom) of a certain type
• any other submission or evidence of the risk of sexual harm posed by the qualifying relevant offender;
• any evidence presented by or on behalf of the relevant offender which demonstrates that the  relevant offender does not pose a risk of sexual harm; and
• any other matter which the relevant chief officer of police considers to be appropriate.