French President Emmanuel Macron will deliver the concluding speech to the conference, which, apart from his appearance, will be behind closed doors.
The revenues of the Islamic State (IS) armed group alone are estimated to have been two billion euros between 2014 and 2016, according to the French president's office.
France is pushing for international coordination and more transparency in financial transactions because it claims that groups such as IS and Al-Qaeda use increasingly sophisticated methods to transfer money.
Is tracking the money effective?
But several experts point out that many terror groups mainly use "low cost" stategies to finance their operations, making the money difficult to trace.
In Don't Follow the Money: The Problem with the War on Terrorist Financing, in Foreign Affairs magazine, Peter Neumann of King’s College London argued against the idea that financial surveillance can be used to control or counter terrorism.
Neumann, who was to speak at the Paris conference, argues that terrorist activity is not particularly expensive, while monitoring financial flows is.
He concluded that since 2001 the "war on terror" has often been costly but mostly ineffective.
French Boko Haram expertMarc-Antoine Perouse de Montclos told RFI that the fact that African terror groups often pledge allegeance to organisations such as IS or Al-Qaeda is misleading.
While it implies major international transactions, these affiliations are often just a label to get better exposure, he argues, and groups like Boko Haram and the Sahel jihadist groups secure most of their income locally, according to the expert.
"They racket merchants, impose taxes on the population, set up raodblocks, steal and taxe cattle or agricultural products," he says. "Taxes on red pepper, fish and local markets constitute a significant part of Boko Haram's income, for instance."
Another example is Somalia, where the al-Shabaab group collects about 15 million euros annually from taxing sugar and 120-160 million euros thanks to coal trafficking, according to the UN.
Also, in order to get weapons and vehicles without leaving a money trail, most of these groups regularly carry out attacks against the security forces to steal their equipment.