Harmonised Inflation indicator of Consumer Prices used in EU and (more recently) UK as a formal measure of inflation. Now referred to as CPI. The CPI excludes a number of items included in RPI eg council tax and a range of owner-occupier housing costs such as mortgage interest payments, house depreciation, buildings insurance, estate agents' and conveyancing fees. The CPI covers all private households, whereas RPI excludes the top 4 per cent by income and pensioner households who derive at least three quarters of their income from state benefits. The CPI also includes the residents of institutional households such as student hostels, and also foreign visitors to the UK. This means that it covers some items that are not in the RPI, such as unit trust and stockbrokers fees, university accommodation fees and foreign students' university tuition fees. Although the same underlying price data is used in most cases to calculate the two indices, there are some specific differences in price measurement. For example, different methods are used in the CPI and RPI to compile the index for new cars.