| Code | Type | Status | Function | Communications Provider | Sub-Allocatee | Trading Name | Name of Service | Description of Service | Use | Change |
| 170 | C | Designated | Cable and Wireless Guernsey Limited | Pre-pay Mobile - Customer Support | ||||||
| 170 | C | Designated | C&W | Internal Use | 06/1997 | |||||
| 170 | C | Designated | C&W Jersey Ltd | Short dial code for access to CSC | ||||||
| 170 | C | Designated | Telewest Communications Plc | Competitions | 11/1996 | |||||
| 170 | C | Designated | Reach Europe Ltd | Internal Use | ||||||
| 170 | C | Designated | COLT | Internal Use | 02/1996 | |||||
| 170 | C | Designated | Orange | Digital Test Message | ||||||
| 170 | C | Designated | C&W | Refer to Operator | ||||||
| 170 | C | Designated | Jersey Telecoms | Voicemail | ||||||
| 1700 | C | Designated | ntl Group Ltd | The Box | 07/1997 | |||||
| 1701 | C | Designated | BT | Internal Use | ||||||
| 17050 | C | Designated | BT | Internal Use | ||||||
| 17051 | C | Designated | BT | Internal Use | ||||||
| 17052 | C | Designated | BT | Internal Use | ||||||
| 17054 | C | Designated | BT | Internal Use | ||||||
| 17070 | C | Designated | Manx Telecom | Circuit Identity Number (Ringback) | ||||||
| 17092 | C | Designated | BT | Internal Use | ||||||
| 17094 | C | Designated | BT | Internal Use | ||||||
| 17095 | C | Designated | BT | Internal Use | ||||||
| 17099 | C | Designated | BT | Internal Use | ||||||
| 17099 | C | Designated | Manx Telecom | Test for 999 | ||||||
| 171 | C | Designated | ntl Group Ltd | CATV Faults | 03/1997 | |||||
| 171 | C | Designated | Reach Europe Ltd | Internal Use | ||||||
| 171 | C | Designated | Orange | Details of Coverage | ||||||
| 171 | C | Designated | ntl Group Ltd | Internal Use | 03/1995 | |||||
| 171 | C | Designated | Cable and Wireless Guernsey Limited | Voicemail Retrieval | ||||||
| 171 | C | Designated | COLT | Internal Use | 11/1996 | |||||
| 171 | C | Designated | Manx Telecom | Internal Use | ||||||
| 171 | C | Designated | C&W Jersey Ltd | Access voicemail | ||||||
| 171 | C | Designated | BT | Internal Use | ||||||
| 171 | C | Designated | Vodafone Ltd | Refer to Operator | ||||||
| 171 | C | Designated | Jersey Telecom | Voicemail service | ||||||
| 1710 | C | Designated | 02 | Call Alert | 10/2004 | |||||
| 1711 | C | Designated | ntl Group Ltd | Internal Use | 02/1997 | |||||
| 1711 | C | Designated | Telewest Communications Plc | Voicemail Access | 04/1996 | |||||
| 1712 | C | Designated | ntl Group Ltd | Internal use | 02/1997 | |||||
| 1713 | C | Designated | ntl Group Ltd | Internal Use | 02/1997 | |||||
| 1714 | C | Designated | ntl Group Ltd | Internal Use | 07/1997 | |||||
| 1715 | C | Designated | ntl Group Ltd | Internal Use | 07/1997 | |||||
| 1716 | C | Designated | ntl Group Ltd | Internal Use | 07/1997 | |||||
| 1717 | C | Designated | ntl Group Ltd | Internal Use | 07/1997 | |||||
| 1718 | C | Designated | ntl Group Ltd | Internal Use | 07/1997 | |||||
| 1719 | C | Designated | ntl Group Ltd | Internal Use | 07/1997 | |||||
| 172 | C | Designated | Orange | Information on Orange telephone features | ||||||
| 172 | C | Designated | BT | Internal Use | ||||||
| 172 | C | Designated | Vodafone Ltd | Refer to Operator | ||||||
| 172 | C | Designated | Telewest Communications Plc | TCC Directory Enquiries | 07/1996 | |||||
| 172 | C | Designated | Jersey Telecom; Cable and Wireless Guernsey Limited | Voicemail Service | ||||||
| 172 | C | Designated | C&W Jersey Ltd | Change voicemail greeting | ||||||
| 1720 | C | Designated | Manx Telecom | Test Numbers | ||||||
| 1721 | C | Designated | Manx Telecom | Test Numbers | ||||||
| 1722 | C | Designated | Manx Telecom | Test Numbers | ||||||
| 1723 | C | Designated | Manx Telecom | Test Numbers | ||||||
| 1724 | C | Designated | Manx Telecom | Test Numbers | ||||||
| 1725 | C | Designated | Manx Telecom | Test Numbers | ||||||
| 1726 | C | Designated | Manx Telecom | Test Numbers | ||||||
| 1727 | C | Designated | Manx Telecom | Test Numbers | ||||||
| 1728 | C | Designated | Manx Telecom | Test Numbers | ||||||
| 1729 | C | Designated | Manx Telecom | Test Numbers | ||||||
| 173 | C | Designated | Orange | Information on Network features | ||||||
| 173 | C | Designated | C&W Jersey Ltd | Set divert to voicemail | ||||||
| 173 | C | Designated | ntl Group Ltd | Internal Use | 03/1995 | |||||
| 173 | C | Designated | Manx Telecom | Internal Use | ||||||
| 1735 | C | Designated | Jersey Telecom | CLI Services | ||||||
| 174 | C | Designated | BT; Telewest Communications; Yorkshire Cable | Internal Use | ||||||
| 174 | C | Designated | Telewest Communications Plc | Business Enquiries | 12/1994 | |||||
| 174 | C | Designated | Orange | Sales Enquiries | ||||||
| 174 | C | Designated | ntl Group Ltd | Internal Use | 01/1995 | |||||
| 174 | C | Designated | Manx Telecom | Engineer Test No (Ringback) | ||||||
| 174 | C | Designated | C&W Jersey Ltd | Removes divert from voicemail | ||||||
| 175 | C | Designated | COLT | Internal Use | 06/1997 | |||||
| 175 | C | Designated | ntl Group Ltd | Install Line Check | 03/1997 | |||||
| 175 | C | Designated | Tele2 (UK) Limited | Engineering Service | ||||||
| 175 | C | Designated | Telewest Communications Plc | Business Fault Reports | 12/1994 | |||||
| 175 | C | Designated | Manx Telecom | Engineer Test No (Ringback) | ||||||
| 175 | C | Designated | BT | Internal Use | ||||||
| 175 | C | Designated | Cable and Wireless Guernsey Limited | Subscriber and line test facility | ||||||
| 176 | C | Designated | BT | Internal Use | ||||||
| 176 | C | Designated | Cable and Wireless Guernsey Limited | Internal Use - cable pair identification | ||||||
| 176 | C | Designated | COLT | Internal Use | ||||||
| 177 | C | Designated | Telewest Communications Plc | "The Box" | ||||||
| 177 | C | Designated | C&W | Video Juke Box (Solent franchise) | ||||||
| 177 | C | Designated | Cable and Wireless Guernsey Limited | Information on Network Features | 05/1995 | |||||
| 177 | C | Designated | Telewest Communications Plc | Voicemail | 01/1997 | |||||
| 178 | C | Designated | Cable and Wireless Guernsey Limited | Prepay mobile credit check | ||||||
| 178 | C | Designated | Jersey Telecom | Internal Use | ||||||
| 178 | C | Designated | Telewest Communications Plc | Business Voicemail | 03/1997 | |||||
| 1781 | C | Designated | Manx Telecom | MT Sales | ||||||
| 1784 | C | Designated | Manx Telecom | Mobile Sales | ||||||
| 179 | C | Designated | Cable and Wireless Guernsey Limited | Pre-pay Mobile - Credit Recharge | ||||||
| 179 | C | Designated | BT | Internal Use | ||||||
| 179 | C | Designated | ntl Group Ltd | Card Services | 05/1997 |