India, Dec. 25 -- The Reserve Bank of India (RBI) has added four more startups to its regulatory sandbox cohort for digital retail payments, taking the total number to six. Fintech startup ToneTag, Mumbai-based PoS smart card provider CityCash, voice biometrics authentication startup Ubona Technologies, and Delhi NCR-based Eroute Technologies have been selected for the cohort.

The four startups join Jaipur-based Natural Support Consultancy Services and Delhi-based Nucleus Software Exports in the cohort. Both companies had already begun testing their payments solutions under the sandbox framework in November this year.

Natural Support Consultancy Services' product 'eRupaya' is a set of near-field communication (NFC)-based prepaid card an...