NPCI is the nodal agency for all retail payment systems under the Jan Dhan scheme.
"NPCI, the umbrella organisation for all retail payments system in India, reached a major milestone of successfully linking 15 crore bank accounts with Aadhaar number," it said in a statement.
Soon all beneficiaries of all types of government subsidiaries/benefit transfers will be brought under the linkage programme, it said.
"The current focus is on linking the bank accounts of 17 crore DBTL (direct benefit transfer) beneficiaries with Aadhaar numbers, latest by June 30, 2015," it said.
"The extent of leakage prevented due to this unique system would be visible on completion of running the scheme for about a year," he added.