The RCEP is expected to eliminate a range of tariffs on imports within 20 years.

It also includes provisions on intellectual property, telecommunications, financial services, e-commerce and professional services.

But it's possible the new "rules of origin" - which officially define where a product comes from - will have the biggest impact.

Already many member states have free trade agreements (FTA) with each other, but there are limitations.

"The existing FTAs can be very complicated to use compared to RCEP," said Deborah Elms from the Asian Trade Centre.

Businesses with global supply chains might face tariffs even within an FTA because their products contain components that are made elsewhere.

A product made in Indonesia that contains Australian parts, for example, might face tariffs elsewhere in the Asean free trade zone.

Under RCEP, parts from any member nation would be treated equally, which might give companies in RCEP countries an incentive to look within the trade region for suppliers.

Article Reference : BBC