Reuters
Britain's Queen Elizabeth II.
The refit will be funded by British taxpayers out of the Sovereign Grant. This is the allowance provided to the Queen by the government to support her official duties.
The Queen received a £40.1 million allowance this year, with a further £13.9 million coming from other sources, such as property rental.
The grant is the Queen's main source of income and contributes to her overall fortune of around £340 million, according to The Sunday Times Rich List.
The Sovereign Grant annual report provides a detailed breakdown of her outgoings - ranging from helicopter transport to utility bills - and it makes for illuminating reading. Here is how the Queen spends her money.