Thinking of arranging wedding insurance? It should cover the eventualities you don't really want to think about - and certainly can't prepare for (such as illness or a supplier going bankrupt). In theory. In reality, most couples don't have sufficient cover. According to wedding insurance comparison website, on average, couples under-insure their wedding by 30 per cent. It compared 2,595 policies bought between May 2009 and April 2010 and found that the average cancellation cover was £12,000, while the average wedding cost £17,000 - leaving a shortfall of £5,000. So make sure you do your sums!