Caldwell: landline numbers and carriers
Caldwell is one of the town-level numbering areas the ACMA register uses under area code 03 (VIC & TAS). The register lists 29 number blocks for it with about 32,000 allocated numbers, held by 18 carriers. A landline that calls you from one of these blocks was issued for the Caldwell area — though the line may since have been ported, and caller ID can be spoofed.
Source: ACMA register, data as of 31/08/2026
The carriers in Caldwell
Caldwell is spread across carriers: SYMBIO NETWORKS PTY LTD leads with 18.8% of allocated numbers, and 18 carriers hold blocks in total. The register names the range holder; individual numbers may operate on another network after porting.
| Carrier | Blocks | Numbers | Share |
|---|---|---|---|
| SYMBIO NETWORKS PTY LTD | 6 | 6,000 | 18.8% |
| SOUL PATTINSON TELECOMMUNICATIONS PTY LIMITED | 2 | 4,000 | 12.5% |
| PRIMUS TELECOMMUNICATIONS PTY LIMITED | 3 | 3,000 | 9.4% |
| TELSTRA LIMITED | 3 | 3,000 | 9.4% |
| NETSIP PTY LTD | 2 | 2,000 | 6.3% |
| OPTUS MOBILE PTY LIMITED | 1 | 2,000 | 6.3% |
| ADARGA PTY LTD | 1 | 1,000 | 3.1% |
| C2A INTERNET.COM.AU PTY. LTD. | 1 | 1,000 | 3.1% |
| CHECK TECHNOLOGY GROUP PTY LTD | 1 | 1,000 | 3.1% |
| CHIME COMMUNICATIONS PTY LTD | 1 | 1,000 | 3.1% |
| LMGPS LTD | 1 | 1,000 | 3.1% |
| NETERA PTY LTD | 1 | 1,000 | 3.1% |
| OPTUS NETWORKS PTY LIMITED | 1 | 1,000 | 3.1% |
| PIPE NETWORKS PTY LIMITED | 1 | 1,000 | 3.1% |
| PIVOTEL SATELLITE PTY LIMITED | 1 | 1,000 | 3.1% |
Number blocks registered for Caldwell
The ACMA allocates geographic numbers in blocks tied to this numbering area. Every registered block for this area is allocated to a carrier.
| Block start | Numbers | Held by |
|---|---|---|
| 0348012000… | 1,000 | VIRTUTEL PTY LTD |
| 0348057000… | 1,000 | SOUL PATTINSON TELECOMMUNICATIONS PTY LIMITED |
| 0348093000… | 1,000 | NETSIP PTY LTD |
| 0348142000… | 1,000 | ADARGA PTY LTD |
| 0348163000… | 1,000 | THE TRUSTEE FOR READING FAMILY TRUST |
| 0348217000… | 1,000 | SYMBIO NETWORKS PTY LTD |
| 0348218000… | 1,000 | SYMBIO NETWORKS PTY LTD |
| 0348247000… | 1,000 | WHY PAY MORE 4 LESS PTY LTD |
| 0348314000… | 1,000 | NETSIP PTY LTD |
| 0348372000… | 1,000 | CHECK TECHNOLOGY GROUP PTY LTD |
| 0348410000… | 1,000 | C2A INTERNET.COM.AU PTY. LTD. |
| 0348443000… | 1,000 | LMGPS LTD |
| 0348476000… | 1,000 | PIVOTEL SATELLITE PTY LIMITED |
| 0348509000… | 1,000 | NETERA PTY LTD |
| 0348543000… | 1,000 | SYMBIO NETWORKS PTY LTD |
| 0358013000… | 3,000 | SOUL PATTINSON TELECOMMUNICATIONS PTY LIMITED |
| 0358089000… | 1,000 | PRIMUS TELECOMMUNICATIONS PTY LIMITED |
| 0358117000… | 1,000 | CHIME COMMUNICATIONS PTY LTD |
Excerpt: the 18 lowest of 29 allocated blocks (source: ACMA register).
Check a number from Caldwell
Worth knowing
- Block data tells you where a line was issued, not who is calling — and scammers routinely spoof local landline numbers to make a call look nearby.
- Learn more: the Australian area codes guide and how caller ID spoofing works.