UK aid donations to the Asian tsunami appeal have reached £76m, the Disasters Emergency Committee has said.
Charities have found it hard to get aid through to some areas
Public contributions to its fund will eventually top £100m, the umbrella group of charities predicted.
The total includes phone and online pledges, but not postal or direct donations to individual charities.
The announcement came as Foreign Secretary Jack Straw said there was "no cap" on the amount of aid the UK Government would offer.
The government has so far committed £50m in aid, after at least 140,000 people died in 11 countries in Asia.
About 1.8m people need food aid, and an estimated five million have been made homeless.
Relief agencies said aid had begun to reach some isolated areas despite the destruction of roads, ports and airfields during the disaster.
Efforts on the Indonesian island of Sumatra, where 94,000 have died, suffered a setback when the only airport in Aceh province was closed for several hours.
It was thought a plane that was flying in aid hit a cow on the runway.
The 12 DEC charities are already working across the affected countries, using local staff as well as dozens flown in from the UK.
A Save the Children flight carrying supplies for 37,000 families arrived in Colombo, Sri Lanka, on Monday.
An Oxfam plane with water equipment for 60,000 people arrived in Medan, Sumatra, two days earlier, but the charity had difficulty getting it further into the country.
On Tuesday evening a British Red Cross plane was due to leave Bristol - bound for the island of Batam in Indonesia.
The destination was chosen as the airports nearer Aceh are so congested with aid flights. On board will be four logistics experts - whose job will be to clear new routes to get aid through to tsunami victims.
The charity is also sending aid flights from nearer the region starting on Wednesday - from Dubai to Indonesia, and three to Sri Lanka from Pakistan, Egypt and China.
Save the Children plans to send another two flights to Indonesia early next week.
The UK government is sending three ships to the region.
Save the Children, which is flying out 4x4 vehicles, survival equipment including tarpaulins, tents, water purification kit and generators said the first task was to prevent further deaths.
"Our first task is to try to make sure that more lives are not loss through illness, through cold," said the charity's director general, Mike Aaronson.
"But also there is the very important task of protecting children - who are very, very vulnerable. Many of them have lost their families."
In Galle, Sri Lanka, Jordan Day, from the World Food programme, said conditions had eased as roads were opened "kilometre by kilometre".
A coordinated operation was ensuring food got to 800 camps.
Mr Day said he was most concerned about those survivors who were not in camps.
"The biggest challenge is getting to those pockets that are the hardest to reach and that harbour vulnerable people," he said.
On Tuesday Chancellor Gordon Brown suggested wealthy G8 countries were poised to freeze foreign debts owed by countries hit by the disaster.
And the Big Lottery Fund - which distributes the largest share of National Lottery money - said it would back any government plan to spend £16.3m of unclaimed winnings
on Asian tsunami aid.
Banks and credit card companies agreed to waive an estimated £300,000 of transaction fees on pledges to all charities.
Each of the 12 DEC charities is given a slice of the donated money depending on its size.
The committee tells each charity how much it can expect to receive, based on donations so far, so that charities are able to start supplying aid immediately.
The DEC said it will be able to claim tax back from the government under the gift aid scheme on about 10 per cent of donations - increasing their value by one third.
A BBC News Special: Asia Remembered, including the three-minutes silence, will be shown on BBC One and BBC News 24 from 1130 to 1215 GMT on Wednesday.