Bengaluru, Nov. 6 -- Merchants were never assured that transactions through the Unified Payments Interface would remain free indefinitely, the Centre has told the Supreme Court while defending the new Merchant Discount Rate (MDR) charges on person-to-merchant transactions above Rs.2,000. In a counter affidavit filed on November 4, following the apex court's directions on September 28, the Union government said the revised MDR model had been under active consideration "well before its introduction, following consultations with stakeholders and their inputs". "No specific assurance of a continuing zero-MDR regime was given to merchants, and the subsidy provided by the State was discretionary rather than obligatory," Centre said. The zero-MDR regime did not eliminate the cost of processing digital payments but shifted the burden to the government and other participants in the ecosystem, it said....