"If you have bought a house together and have lived together for more than 3 years then there is no inheritance tax to pay on the death of your partner. "
Sorry to contradict, but this is quite wrong. In these circumstances, there would be no inheritance tax to pay on the house PROIVIDED that you own no other house. But there may be life insurance, death in service lump sums, stocks, savings etc. These will all be liable to inheritance tax. The reality is that married couples enjoy a whole range of tax advantages