HMRC Guidance : Reasonable care: tax returns and other documents
https://www.gov.uk/guidance/reasonab...ther-documents

Everyone has a responsibility to take ‘reasonable care’ over their tax affairs. This means doing everything you can to make sure the tax returns and other documents you send to HM Revenue and Customs (HMRC) are accurate. If you don’t take reasonable care HMRC will charge penalties for inaccuracies.


Article on AccountingWeb :
https://www.accountingweb.co.uk/tax/...easonable-care

From 16 November 2017, a person who enters into a tax avoidance scheme cannot rely on advice from a third party (including a barrister) unless it meets certain criteria. This broadly means that the adviser must be chosen by the taxpayer and not the tax scheme promoter.