The announcement came as it suspended its dividend and reported a loss in the first half of its financial year.
De La Rue said its warning was based on a worst-case scenario.
However, it concluded that there was “a material uncertainty that casts significant doubt on the group’s ability to operate as a going concern”.
UK-based De La Rue prints cash for about 140 central banks and employs more than 2,500 people globally.
All current Bank of England banknotes are printed by the firm at a site in Debden, Essex.
It is unclear what would happen if the firm got into difficulties, but it is likely that a rival would take over its Bank of England contract. Its main competitors are all based outside the UK.
