This Practice Note explains the purpose and scope of mitigation given on behalf of defendants convicted of criminal offences by the criminal courts in England and Wales, in order to reduce the sentence imposed by the courts. It covers the law relating to mitigation, which is any aspect of a case that reduces the severity of the sentence passed, either the length of sentence or type of sentence imposed. It explains the factors that determine sentence, the purpose of mitigation, what is meant by personal mitigation and a suggested structure of a plea in mitigation and provides links to the Sentencing Council’s sentencing guidelines including the General guideline—overarching principles (the General guideline) which provides expanded explanations for aggravating factors and mitigating factors, culpability and harm and applies to all individual offenders aged 18 or over and to organisations who are sentenced.