Robert Go, Jakarta – Indonesia would gain an additional 60 trillion rupiah (S$10.8 billion) a year if citizens paid their proper taxes, according to an aide to new Finance Minister Rizal Ramli.

Indonesians were notorious for dodging their taxes by bribing collectors and under-reporting their incomes, said Mr Anggito Abimanyu.

Of the country's population of 210 million, only 1.5 million have tax files. Earlier this week, Director-General of taxes Hadi Purnomo said that as many as 600,000 of Jakarta's eligible taxpayers did not have proper papers and did not pay taxes.

Just days after taking over at the Finance Ministry, Dr Rizal has moved aggressively on one of his pet projects: Filling government coffers with more tax revenue. And the signs are there that he might succeed.

Hundreds of rich Indonesians had voluntarily registered with local tax offices as soon as authorities started knocking on doors and demanding to see tax documentation in exclusive Jakarta neighbourhoods, said senior Finance Ministry officials. Mr Anggito added: "When they heard about the taxmen coming, they flocked to tax offices and registered themselves. It is sad to see how many people have not paid proper taxes. This can be positive for us, however, as it means we can step up collection and increase state revenues."

Mr Nono Hanafi, a spokesman for the tax directorate at the Finance Ministry, said: "Our tax ratio is very low, at 11.7 per cent of GDP. This ratio is about 16 per cent in the Philippines and is much higher either in Singapore or Malaysia. The 'registration update' will increase tax participation. We are adding offices to make enforcement more efficient and to allow easier registration for citizens."

The two officials said the government wanted to see tax revenues reaching at least 15 per cent of Gross Domestic Product within the next three or four years.

While agreeing that many Indonesians neglected their tax duties, homeowners in neighbourhoods being targeted by the taxmen expressed doubts about the government's ability to execute its plans efficiently. A resident of the Pondok Indah neighbourhood said: "They've come to my door and I have registered to avoid problems. But I'm not sure if the bureaucrats can effectively follow through, especially if all the money is now supposed to go to the state."

A businessman with a house in Menteng, where former President Suharto's Cendana complex is located, said: "If we have to pay the full amount, OK. But how can we be sure the money goes for the right purpose?"

Mr Nono, however, reported that there would be no letting up in the government's pace and that it planned increase the scope of the door-to-door audits."Less than 50 per cent of residents in some areas had proper papers, but after our visits, we estimate that over 90 per cent of residents are properly registered now. That is an encouraging development," he said.

The "targets areas" were those where the cost of an average home was more than 3 billion rupiah. "We have just begun to scratch the surface. The result will be very visible in next year's income-tax revenue."