140 series refers to a TRAI-mandated phone number prefix (starting with 140) assigned to registered telemarketers in India for making promotional, service, and transactional voice calls. These 10-digit numbers to help users identify telemarketing calls, reduce spam, and ensure compliance with Do Not Disturb (DND) regulations. Visit: https://www.c-zentrix.com/blog/140-number-series-guide-india