Use a long code when you need customers to type a reply: competitions and voting, product and service feedback, campaigns and promotions, or a direct response channel printed on TV, print and online ads. It is also a natural follow-up channel for bulk SMS campaigns, because every message can carry a keyword that invites a reply.
If you only need a one-tap signal of interest, a missed call number is even simpler, and a two-way campaign can combine missed call registration with long code replies. For voice-first support, pair your long code with a 1800 toll-free number. If your audience prefers chat, the WhatsApp Business API offers rich two-way conversations.
Outbound messages you send from SMSGatewayHub still follow TRAI DLT rules for sender IDs and templates; inbound replies to your long code are received on the virtual number and do not need a template.