The associated revenue losses with the illicit market in petrol in Northern Ireland were negligible in 2010-11 and 2011 -12. The illicit market for diesel was estimated to be 12% to 13% of the total market in Northern Ireland in 2011-12. This is a tentative estimate that was published in ‘Measuring Tax Gaps 2013’: http://www.hmrc.gov.uk/statistics/tax-gaps/mtg-annex2013.pdf Estimates for previous years are not available as it is not possible to split out the cross border shopping element of the total non-UK duty paid figure for diesel. Estimates of revenue lost due to illegal trading in cigarettes, spirits and other counterfeit goods in Northern Ireland are not available. Estimates of the total illicit market for cigarettes, spirits and other goods subject to excise duty are available at UK level for 2011-12. These are published in ‘Measuring Tax Gaps 2013’. Additionally, estimates of the illicit market in 2012-13 for cigarettes and hand-rolling tobacco in the UK are available in a supplementary publication. http://www.hmrc.gov.uk/statistics/tax-gaps/ttg-2013.pdf