I thought this piece of info would be useful to you all, in-case you have not got hold of these till now:
| Service Provider | Code | Service Area | Code |
| Aircel, Dishnet Wireless | D | Andhra Pradesh | A |
| Bharti Airtel | A | Assam | S |
| BSNL | B | Bihar | B |
| BPL Mobile/Loop Telecom | L | Delhi | D |
| Datacom Solutions | C | Gujarat | G |
| HFCL Infotel | H | Haryana | H |
| Idea Cellular | I | Himachal Pradesh | I |
| MTNL | M | Jammu & Kashmir | J |
| Reliance Communications | R | Karnataka | X |
| Reliance Telecom | E | Kerala | L |
| S tel | S | Kolkata | K |
| Shyam Telecom | Y | Madhya Pradesh | Y |
| Spice Telecom | P | Maharashtra | Z |
| Swan Telecom | W | Mumbai | M |
| Tata Teleservices | T | North East | N |
| Unitech Group | U | Orissa | O |
| Vodafone Group | V | Punjab | P |
| Rajasthan | R | ||
| Tamil Nadu | T | ||
| UP-East | E | ||
| UP-West | W | ||
| West Bengal | V |
So, combination of these two constitutes the first two digit of “Sender” followed by an hyphen (-) & actual sender name.