As technology improves, the risk from forged banknotes becomes greater. As a result, since the Second World War, the designs of Bank of England notes have changed more and more frequently and become more and more complex.

The first new design was by Stephen Gooden for the £5 note. This was issued in February 1957 and is known as the Series B or Helmeted Britannia. Designs were produced for the 10/- and £1 notes, but Gooden died before he could produce a design for the new £10 note. In 1956 the Queen had consented to have her portrait appear on Bank of England notes and Gooden's 10/- and £1 notes were never issued.
A slight variation in the design of the £5 appears with a white symbol denoting the denomination on the reverse rather than a blue symbol.