Stung by the poor response to the one-time black money compliance window that ended on September 30, finance minister Arun Jaitley on Sunday said those who had undeclared foreign assets but could not use the opportunity to come clean would face the stringent provisions of the new black money law.

Arun Jaitley also hinted at an impending crackdown on domestic black money. The threshold for compulsorily quoting permanent account number (PAN) may be lowered in case of various transactions and in case of many transactions where PAN is not mandatory, it could now be made a must.

Only 638 returns were received under the three-month compliance window, offering Rs 3,770 crore of previously unreported foreign wealth for 60% tax and penalty in return for immunity from prosecution under the stringent black money law.

“These declarants can now sleep well. For those who have undisclosed foreign assets but have failed to file such a declaration will now be subjected to penal provisions of this law,” Jaitley said in a Facebook post.

Quoting of PAN number is now mandatory while opening a bank account or making a bank deposit exceeding Rs 50,000, PAN needs to be given for other transactions above specified thresholds like purchase of mutual fund units above Rs 50,000. In the FY16 Budget, Jaitley had proposed making quoting of PAN mandatory for all sales and purchases of over Rs 1 lakh.

If caught, those with unaccounted wealth abroad who refused to use the compliance window would be liable to pay 120% of assets in tax and penalty. Also, the assets would be confiscated and wrongdoers could face imprisonment up to 10 years. “Those with illegal assets abroad, who have failed to make a declaration, would now stand the risk of information relating to them eventually reaching the Indian tax authorities,” Jaitley said.

He said tax evaders won’t be able to hide information pertaining to their black money after India signed a comprehensive information exchange agreement with the US recently, while it will also benefit from a G-20 backed multilateral automatic exchange of information agreement, which will come into force from 2017.

Pointing out that the bulk of black money is still within India, Jaitley said a separate drive would shortly begin

to incentivise use of plastic money/e-transactions while disincentivising cash transactions.

“The government is at an advanced stage in considering the requirement of furnishing PAN card details if cash transactions beyond a certain limit are undertaken,” Jaitley said.

The monitoring regime for income tax is being strengthened to detect large cash withdrawals, or large cash transactions which enter the system. Also, once the proposed goods and services tax regime is implemented, it would be easier to track cash transactions made for commodities like gold.

Acknowledging that the high taxation regime in the past encouraged tax evasion, the minister said the current government intends to tax at reasonable rates.