Household wealth inequality in the UK is high and has slightly increased in the past decade due to rising financial asset prices. Data limitations make it hard to fully understand the distribution and size of wealth. The main survey of UK household wealth captures most of the distribution, but around £800 billion of wealth from the wealthiest households is missing. There is evidence suggesting that high-wealth families may undervalue their assets, with the true value of household wealth in the UK estimated to be 5% higher than reported in surveys.