The Brihanmumbai Municipal Corporation (BMC) working to implement a new property tax regime, plans to bring all properties, including slums, under the tax bracket. However, while the civic body plans to collect tax from June, 2015, the corporation has still not come up with a method to assess the worth of slum properties even after squeezing the administration's collective brains for more than six months.

Municipal commissioner Sitaram Kunte announced in the recent budget that slums will be brought under the property tax net. But the question bothering the administration is: On what basis does BMC collect property tax from citizens? The corporation is mulling over the possibility of whether to bring amendment in the existing law or bring a new law altogether.

Officials from the assessment and collector's department, which collects property tax, have been racking their brains for half a year now about the formula to assess tax on slums. They have prepared drafts plans and various formulae on the possible methods of collection, but which one will prove foolproof has not been ascertained. "No decision has been taken yet. The department is working out on possible solution which will pass the acid test successfully," said a senior civic official.

This will be the first time in the history that the civic body will impose property tax on slums. "Hence, a lot of trial-and-error formulae are being worked out in the house. Lot of brainstorming is going on. All aspects including regulations, demographics, expanse of each unit, real estate value etc will have to be considered while preparing the formula of collecting tax from slum dwellers. Officials are facing technical difficulties while implementing the decision," said an official.

An official pointed out that to bring slums under the tax net, all slum-like buildings will have to be physically measured and the records have to be generated. For this, BMC will need manpower and money. "Even with the manpower and money, it will take at least two years to complete the job," said official.

Again, the BMC will not be able to tax the slums as per the capital value based tax system as it has to be measured considering the area and ready reckoner rates. If BMC implements capital value based tax system, it might face a legal challenge.

The biggest challenge faced by the civic body is that slum structures are not used only for the residential purpose, but for commercial, industrial and so on. Furthermore, even in commercial and industrial areas, there are different categories for the civic body to sift through .