Notice 160 has been updated to take account of the new appeals process and penalty regime that came into force on 1 April 2009.
If HMRC identify irregularities due to conduct involving dishonesty, a civil evasion penalty will normally be applied. If an irregularity due to deliberate behaviour is identified, HMRC will normally charge a penalty for deliberate inaccuracies or a penalty for deliberate and concealed inaccuracies. The penalty applied depends upon the tax period in which the irregularities occur and will be a percentage of the tax under declared or over claimed.
Notice 160 also outlines how taxpayers can ask for a local reconsideration of, and/or appeal to the independent First-tier Tribunal against, the amount of any tax assessment and other related assessment issues. The taxpayer can also appeal in the same way against the imposition, and amount of, any penalty. For full details of the amendments to Notice 160 see here