The government hopes to choke off funding for attacks
Chancellor Gordon Brown promised "decisive action" both nationally and internationally, against the financing of terrorism.
"In every area where we can work together with our neighbours around the world we will be taking action," he said.
Among proposed measures are more police powers to track suspicious bank accounts even without evidence of a terrorist link - as already happens in Northern Ireland.
The National Criminal Intelligence Service will get more powers and money to track terrorist funds.
It is understood that Mr Brown will press EU leaders to implement urgently the money laundering directive being considered by the European Parliament.
And Britain is calling for global watchdog the Financial Action Task Force to press all countries to report transactions suspected of being linked to terrorism, even when the money comes from legitimate sources.
Britain will also urge the United Nations to be more vigorous in its sanctions against Afghanistan to prevent money being taken across its borders.
Bin Laden probe
Some action has already been taken by Mr Brown and the UK financial institutions.
An updated list of suspected terrorists is being sent to US financial institutions so they can check for links to Osama Bin Laden - suspected of carrying out the attacks.
Barclays Bank has agreed to freeze an account used by a suspected associate of Bin Laden's who is currently awaiting extradition from the UK to the US.
Investigations are under way into unusual share price movements in the weeks before the attacks.
It is thought Bin Laden, or some of his supporters, may have carried out trades designed to profit from falls in stocks likely to be affected, such as reinsurance, airlines and armaments.
Rate cuts
The international community is also acting to try to bolster the global economy after the attacks.
On Tuesday the Bank of England followed the US and many other European countries in cutting interest rates.
Mr Brown acknowledged that the global economy was facing "testing times".
But he said there was determination around the world to maintain financial stability.
"I think the combination of getting the markets moving... working with oil producers... and now with these interest cuts around the world we are showing that we can take decisive action," he said.
"That is not to say that things are not difficult because there will be an impact on the airlines, on the insurance industry and everything else, but we are showing our resolve to maintain the conditions."