The requirements mean companies will need to provide evidence on how they plan to adapt and decarbonise as the UK moves towards a net zero economy by 2050.
The plans were announced on Wednesday as part of sweeping reforms Chancellor Rishi Sunak hopes will halt so-called greenwashing.
PRCA Climate Misinformation Strategy Group lead John Brown said: "A big part of what the strategy group has called for is around transparency and accountability, especially when it involved putting some proof behind the net-zero pudding. The news today that a plan to oblige large organisations to report on net-zero transition plans in the next couple of years is a welcome step forward and will ensure urgency and action.
"It's vital, however, that this announcement doesn't trigger a race to carbon offsets. There needs to be greater emphasis on addressing the unregulated offset markets and establishing best practice for organisations."
Brown, who is CEO of PR agency Don't Cry Wolf, added: "Recently, the WWF highlighted that just 20 of the FTSE 100 have reported on their net-zero progress, despite many businesses making big sweeping statements about their commitment to change. We hope today's announcement will ensure evidence goes hand-in-hand with noisy PR campaigns."