"Why wait till March 31, 2017? Declare your black money now or get penalised later!" the income tax department said in an advertisement in newspaper dailies here.

It asked black money holders to declare their unaccounted income under the Pradhan Mantri Garib Kalyan Yojana (PMGKY) scheme till March 31. They could make the deposits in the form of cash or in an account with bank or post office or specified entity, with a tax, surcharge and penalty totaling up to 49.90 per cent, it said.

The income tax department has ensured complete confidentiality and immunity in respect of the declarations made under the scheme.

Mandatory deposit of 25 per cent of the undisclosed income will be made in PMGKY. The deposits will be interest free and have a lock-in period of four years.

The department warned that it has all the information about the deposits made by people and non-declaration of unaccounted income will be liable to tax, surcharge and cess at the rate of 77.25 per cent alongwith penalty, prosecution and enforcement actions.

"As the last date is approaching the government is going all the way to make non tax-compliant declare their income under PMGKY," tax expert Pritam Mahure told IANS.

"Success of PMGKY will depend on how much money is disclosed till March 31," he said.