Wikipedia
The Keeper of the Privy Purse and Treasurer to the King/Queen (or Financial Secretary to the King) is responsible for the financial management of the Royal Household of the Sovereign of the United Kingdom.
He is assisted by the Deputy Treasurer to the King/Queen for the management of the civil list, and the royal palaces presentation fund. The Director of Finance also has charge of financial management of all funds covered by civil list and grant-in-aid.
He is also assisted by the Deputy Keeper of the Privy Purse for semi-private concerns, such as racing stables, the Royal Philatelic Collection, Royal Ascot, the Chapel Royal, Page of Honour, Military Knights of Windsor, Royal Maundy, the Royal Victorian Order, grace and favour apartments, and the Duchy of Lancaster. These are funded from the Privy Purse, which is drawn largely from the Duchy of Lancaster. The Keeper of the Privy Purse meets the Sovereign at least weekly.
The current Keeper of the Privy Purse and Treasurer to the Queen is Sir Alan Reid, GCVO. The Deputy Keeper of the Privy Purse is Sir John Parsons.