De La Rue, the company that prints the UK’s banknotes, has said there is a risk that the firm will collapse if its turnaround plan fails to work.
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.
The BBC understands that preparations have already been made for the launch of the new £20 note featuring artist JMW Turner, printed by De La Rue, which enters circulation on 20 February next year.