NEW DELHI: With 99 per cent of the demonetised 500 and 1,000 rupee notes having returned to the banking system, has demonetisation failed to serve its purpose? That may not be true, because Project Demonetisation is not over with the mere return of junked notes. The more important part begins now, or has already begun. With so much of the cash in the mainstream now, the government will scrutinise the deposited cash and a good part of it may turn out to be black money.Demonetisation has already expanded the tax base. Individual income tax returns jumped 25% so far in the current financial year as the authorities turned up the heat on evaders after demonetisation. The returns filed by individuals were 25.3% higher at 2.79 crore as of August 5, an addition of about 55 lakh from 2.23 crore in the corresponding period of 2016-2017. Growth in filing in the previous year was 9.9%.An estimated Rs 15.4 lakh crore worth old 500 and 1000 rupee notes were demonetised on November 8. As most of it has come into the banking system, the money will be under the tax scanner. Of course, the black part of this money will become white, but not before it is taxed. Such a large amount entering the tax system is itself a success of demonetisation which was touted as a drive against black money.The tax authorities have identified more than 400 benami transactions up to May 23, and the market value of properties under attachment is more than Rs 600 crore. Expect more of this happening now.Not just that. Money trails generated by demonetisation resulted in identification on two lakh shell companies. Transactions of more than 3 lakh registered companies are under the radar of suspicion while 1 lakh companies were struck off the list, the government has said. It has already identified more than 37,000 shell companies which were engaged in hiding black money and hawala transactions. Around 163 companies which were listed on the exchange platforms were suspended from trading, pending submission of proof documents.All these consequences of demonetisation mean a major impact on the country's black-money economy.The government is deploying advanced data analytics tool to scrutinise the deposited money. Demonetisation cast a harsh light on hidden hordes of black money which has found its way to banks through various routes. Now the government has to separate the black from white and tax it. Demonetisation will be over once the government accounts for all the returned money.