In the United Kingdom, the Violent and Sex Offender Register (ViSOR) is a database of records of those required to register with the Police under the Sexual Offences Act 2003, those jailed for more than 12 months for violent offences, and unconvicted people simply thought to be at risk of offending (most famously Andrew Mickel). In response to a Freedom of Information Act request in 2009, for example, Greater Manchester Police reported that of 16 people in their area placed on ViSOR since 2007, 4 (25%) had not been convicted. The Register can be accessed by the Police, National Probation Service, and HM Prison Service personnel. Private companies running prisons are also granted access.  It is managed by the National Policing Improvement Agency of the Home Office.
Notification Periods for offenders Sentenced under Sexual Offences Act 2003 
- Imprisonment for life or for 30 months or more, imprisonment for public protection, or admission to hospital under restriction order, or subject to an Order for Lifelong Restriction: Notification Period: Indefinitely
- Imprisonment for more than 6 but less than 30 months: Notification Period: 10 years
- Imprisonment for 6 months or less, or admission to hospital without restriction order: Notification Period: 7 years
- Caution: Notification Period: 2 years
- Conditional discharge or (in Scotland) a probation order: Notification Period: Period of discharge or probation period
- Any other: Notification Period: 5 years
- Finite notification periods are halved if the person is under 18 when convicted or cautioned.
Lifelong registration has recently been successfully challenged in the High Court; this challenge was upheld on appeal to the Supreme Court . It was ruled that Article 8 of the European Convention of Human Rights is not compatible with it.
The requirement to register was originally imposed by the Sex Offenders Act 1997. The 1997 Act was amended by the Criminal Justice and Court Services Act 2000 to include the requirement to notify police of any foreign travel arrangements. The 1997 Act was repealed by the Sexual Offences Act 2003 which completely reimplemented the provisions of the 1997 Act.
The ViSOR database holds name and address records, photographs, risk assessment, offenders' modus operandi, and an audit trail. The Police National Computer is linked to ViSOR. According to the National Policing Improvement Agency 77,000 records of named individuals are maintained on the database. 
Obligations of offenders
Upon initial registration, offenders must provide the police with the following information:
- Full name
- Home address
- Date of birth
- National Insurance number
- Vehicle details (if the offender has a vehicle): make, model, colour and registration number of vehicle(s)
Offenders must inform the police within 3 days if there are any changes in their name, address or vehicle details.
Offenders must also inform the police at least 7 days in advance if they intend to leave the United Kingdom for a period of 3 days or more, and they must register any addresses in the UK at which they stay for more than a total of 7 days within any 365-day period.
Offenders must confirm their registration annually . That is, if they have not needed to inform the police of any changes above, they must attend a designated police station to register if they have not done so for a year. Failure to comply is an offence, subject to a penalty of up to five years imprisonment.
Construction of the ViSOR application began in January 2003, with a first release of functionality to a pilot site November 2003. The system was subsequently rolled out to a further three pilot sites during early to mid 2004. National (UK) rollout began November 2004, and was completed April 2005. For a government IT project this appears to have been considered a relatively quick and successful development and deployment.
ViSOR is now in use across all 52 geographic police forces in the UK. Roll out to the Prison and Probation services of England and Wales was scheduled for 2006/7, but was considerably delayed and was only completed in the autumn of 2008.
European Sex Offender Database
MEPs have shown some support for a European Sex Offender Database. However it will be many years, if ever, before it comes to fruition and even then it may not be effective. A 2007 NSPCC report suggested the failure of EU countries to share criminal records properly and the fact that in their opinion this was leaving children at risk in the UK.
However, though some individual MEPs position may be favourable, there are a number of European countries (Spain, Germany, Italy and France) that in the past have clearly stated that Sex Offenders' Registration as in the UK is a breach of the European Convention of Human Rights making it very unlikely to be implemented EU wide.
- Section 82 of the Sexual Offences Act 2003
- Section 66 and Schedule 5
-  National Policing Improvement Agency Business Plan 2009-10. Page 32.
- Section 83 of the Sexual Offences Act 2003
- MEPs 'want EU sex offender list'
- The failure of EU countries to share criminal records leaves children at risk
- Sex Offenders Act 1997
- WikiCrimeLine Violent and Sex Offenders Register
- Dangerous Persons Database – ViSOR: National Policing Improvement Agency
- Lifelong registration is not compatible with the European Convention of Human Rights