LONDON (Reuters) - Companies must warn investors in their annual reports about the ongoing risks posed by Britain potentially leaving the European Union or lower commodity prices, the UK's accounting watchdog said on Tuesday.
Many companies are in the process of compiling their annual reports for 2015 and have asked the Financial Reporting Council (FRC) for more guidance on what to include this year.
"Asset prices have been volatile, oil prices have moved further, in certain jurisdictions interest rates have fallen, and the UK's referendum on EU membership has been announced," FRC Chief Executive Stephen Haddrill said in a letter to companies published on Tuesday.
Accounts offer investors a snapshot of a company's health at the end of the reporting period, but Haddrill said events or information subsequently coming to light which affect valuations may need to be disclosed.
"The range of outcomes you have considered to be reasonably possible may need to revisited," he said.
"Financial reporting standards require companies to disclose material post balance sheet events including the nature of each event and its estimated financial impact," Haddrill added.
Many of the biggest companies listed in Britain are heavily exposed to oil and commodity markets which have suffered a beating.
Banking shares have also suffered since the start of the year on worries over how they can make money when interest rates are falling into negative territory in some cases.
(Reporting by Huw Jones; Editing by Keith Weir)