Not technically a default, but the UK did receive an IMF bailout in 1976

http://www.nationalarchives.gov.uk/cabinetpapers/themes/imf-crisis.htm

1932 was not a default - 5% War Loan was a callable security and holders had the choice at the time of being paid in full or swapping for a new security of 3.5%, principal to be payable after 1952 at a time of the governments choosing. It was paid out in full in March 2015, albeit eroded by decades of inflation.

There are still technically World War I debts owed to and by Britain. Since a moratorium on all debts from that conflict was agreed at the height of the Great Depression, no repayments have been made to or received from other nations since 1934. and the UK Government consider them all to have lapsed. More was owed to the UK than borrowed.