cautions

[bartyarmy]

when is a minor shoplifting caution is spent

[Buenchico]

The Rehabilitation of Offenders Act (which makes provision for most offences to become spent after a certain period of time) makes no reference to cautions because a caution is not a conviction and therefore it can't (officially) ever become spent. (Only convictions can become spent).

The police are permitted to delete records of cautions from their records after a certain period of time (which depends upon the nature of the offence, and whether the offender has any convictions, but is usually 5 years) but they're not obliged to do so.

However, it's generally held that a caution can be disregarded after 5 years. This document, from the National Association for the Care and Resettlement of Offenders, explains further:
http://www.lawontheweb.co.uk/rehabact.htm

Chris