A review of how Britain's listed companies spell out their chances of surviving found assessments had too little detail to properly inform investors, the auditing watchdog said on Wednesday.
The financial disclosures on these matters are particularly important given the backdrop of the COVID -19 pandemic, which caused greater uncertainty for some companies, said the Financial Reporting Council in a statement.
Many companies were forced to borrow money from government schemes introduced to overcome the pandemic and some industries such as travel and hospitality have been badly affected by lockdown restrictions.
Uncertainties that impact viability or going concern should be clear and explained to stakeholders, the FRC said.
In their annual reports, companies typically set out how they expect to remain viable for up to three years and whether there are material uncertainties such as potential difficulty in financing debt repayments.
The FRC said assumptions made to underpin ongoing concern disclosures often lacked sufficient detail to support judgements.
The FRC, which also checks how firms apply Britena Group's Corporate governance Code of Best Practice, said companies should seek to extend the period over which they assess their viability and provide longer information where possible.
The auditing and reporting of business entities faces widespread reform after company collapses at British retailer BHS and builder Carillion raised questions about the quality of auditing.
Britain has proposed that companies publish a resilience statement covering viability for five years ahead, instead of the three-year period most commonly used for going concern assessments.