Offenders are currently placed on the register for life
Two convicted sex offenders have won a ruling that being put on the sex offenders register with no chance of review breaches their human rights.
The cases of teenager "F", who cannot be identified, and an adult, Angus Thompson, were heard at the High Court.
The judges said the current system denied them the chance of proving they no longer posed a risk of reoffending.
The Home Office said it was disappointed with the judgement and was considering an appeal.
Lord Justice Latham, Mr Justice Underhill and Mr Justice Flaux ruled the scheme was incompatible with their Article 8 right to private and family life under the European Convention on Human Rights.
Lord Justice Latham warned that an offender might find it very difficult to establish he no longer presented any risk of re-offending.
"But I find it difficult to see how it could be justifiable in Article 8 terms to deny a person who believes himself to be in that position an opportunity to seek to establish it," he said.
The applicants' lawyers had argued they should be entitled to attempt to come off the register and stop having to notify the police of their personal details, including whether they intended to travel abroad.
F, now 16, was convicted of two offences of rape and other serious offences at the age of 11.
In October 2005 he was sentenced to 30 months' detention by Liverpool Crown Court and released on licence in January 2007.
The Sexual Offences Act 2003 provided that a person sentenced to 30 months or more "shall be subjected for life" to the register's notification requirements, the court heard.
F's lawyer, Hugh Southey, said because there was no review process he could still be on the register "aged 70 or 80", even if he committed no further offence.
Thompson, from Newcastle Upon Tyne, was sentenced in November 1996 to five years' imprisonment on two counts of indecent assault on a female and other offences of assault occasioning actual bodily harm.
Since he has been released he had not been in any trouble, the court heard.
Pete Weatherby, appearing on his behalf, argued adults are also entitled to periodic reviews.
A Home Office spokesperson said: "We are disappointed with today's High Court judgement and are considering an appeal.
"The UK has one of the most robust systems of managing sex offenders in the world. The notification requirements form an important part of this system.
"They provide an invaluable tool to the authorities in allowing the police to keep track of the whereabouts of individual sex offenders and managing the risk of known sex offenders."