Option 1: conditional call forwarding (keep your number)
- Get a virtual number from a provider (Twilio, Plivo, Telnyx, or Exotel in India).
- On your existing phone line, forward calls "on busy / no answer" to that number (your carrier explains the code, often *61* or **61* on mobiles).
- The provider reports the unanswered call to your text-back system, which replies within seconds.
Option 2: provider webhook
If your business phone already runs on a cloud provider, point its call-status webhook at your text-back system; unanswered or voicemail statuses trigger the reply.
Country notes
| Country | SMS | |
|---|---|---|
| India | Approved utility template | DLT registration of entity, header and template required |
| United States | Approved template (WhatsApp less common) | A2P 10DLC brand and campaign registration |
| United Kingdom | Approved template | Sender ID rules; consent for marketing |
| UAE | Approved template (WhatsApp dominant) | TDRA sender registration |
Wording that works
"Hi, sorry we missed your call to Bright Dental. How can we help? Reply here or book a time: [link]". Name the business, apologise briefly, ask one question and offer a booking link. Include opt-out wording where required.
Frequently asked questions
Is missed-call text-back legal?
Replying to someone who just called you is generally a service message, but SMS still needs sender registration in many countries, and marketing follow-ups need consent.
Do I need a new number?
No. Conditional call forwarding keeps your number.
How fast should the text go out?
Within a minute, ideally seconds, while the caller still has the phone in hand.
Sources
- Pricing on the WhatsApp Business Platform - Meta for Developers, 2026.
By the Nomisly Product Team. Updated . Corrections: tell us.