Signage is seen outside the European Central Bank (ECB) building, in Frankfurt, Germany, July 21, 2022.
The British government, which received 120 billion pounds in profits from the BoE since 2009, has already earmarked a transfer of 11 billion pounds for the central bank.
It will contribute to losses of around 40 billion euros for euro zone central banks next year, according to Morgan Stanley.
They have all warned of upcoming losses and the Dutch central bank openly said it risked needing a bailout, although finance minister Sigrid Kaag later cautioned this was "not yet on the table".
By contrast, central banks with less cash and higher-yielding bonds in Italy, Spain and Greece were likely to fare better.