Derby: landline numbers and carriers

Derby is one of the town-level numbering areas the ACMA register uses under area code 08 (SA, WA & NT). The register lists 34 number blocks for it with about 46,000 allocated numbers, held by 18 carriers and spread over the 0891… and 0851… dialling prefixes. That makes Derby the 64th largest of 640 numbering areas under 08 by block count, with 0.16% of the area code's allocated numbers. A landline that calls you from one of these blocks was issued for the Derby area — though the line may since have been ported, and caller ID can be spoofed.

Source: ACMA register, data as of 16/10/2026

34blocks in the register
18carriers with allocations
46,000allocated numbers
1991first allocation

Where Derby is

State or territory
Western Australia
Council area
Derby-West Kimberley
Local time
— AWST, UTC+8, no daylight saving
Number format
08 91xx xxxx; from overseas +61 8 91xx xxxx
Nearest numbering areas
Roebuck (Ext) (135 km), Broome (168 km), Fitzroy Crossing (220 km), Hall's Creek (WA) (434 km), Telfer (464 km)

Locality, council and state: ABS ASGS Edition 3 (CC BY 4.0). Distances are straight-line between localities.

Map of the Derby numbering area in Western Australia and the nearest other numbering areas
Shaded: Derby-West Kimberley council area. The ACMA doesn't publish numbering-area boundaries, so the dot marks the Derby locality rather than an exact outline; the inset shows where the map sits in Australia. Boundaries: ABS (CC BY 4.0).

How Derby was numbered

The oldest block in Derby was allocated on 30 June 1991 and is held today by TELSTRA LIMITED; the newest on 19 August 2026 to SYMBIO NETWORKS PTY LTD. Most of the area's blocks — 7 of 34 — date from 2020–2024, but allocations here span 35 years. 28 of the blocks are the standard 1,000-number size. 6 allocated blocks have changed hands since they were first issued: the register still names AAPT LIMITED, ENGIN PTY LIMITED, GOTALK LIMITED, IPTEL PTY LIMITED, IVOX PTY LTD and TWILIO AUSTRALIA PTY LTD as original allocatees of blocks now held by other carriers.

PeriodBlocks allocated
1990–19945
2000–20043
2005–20094
2010–20146
2015–20195
2020–20247
2025–20294

The carriers in Derby

Derby is spread across carriers: TELSTRA LIMITED leads with 30.4% of allocated numbers ahead of SYMBIO NETWORKS PTY LTD on 13%, and 18 carriers hold blocks in total. TELSTRA LIMITED has the longest tenure, with a block dated 30/06/1991; SYMBIO NETWORKS PTY LTD received the newest, on 19/08/2026. SYMBIO NETWORKS PTY LTD (3), SOUL PATTINSON TELECOMMUNICATIONS PTY LIMITED (1) and PRIMUS TELECOMMUNICATIONS PTY LIMITED (1) hold blocks originally allocated to another carrier.

CarrierBlocksNumbersShareFirst blockLatest block
TELSTRA LIMITED614,00030.4%30/06/199120/05/2011
SYMBIO NETWORKS PTY LTD66,00013%29/06/200519/08/2026
OPTUS NETWORKS PTY LIMITED34,0008.7%16/06/200519/05/2022
SOUL PATTINSON TELECOMMUNICATIONS PTY LIMITED24,0008.7%30/03/200014/07/2016
PRIMUS TELECOMMUNICATIONS PTY LIMITED33,0006.5%24/12/200403/02/2012
NETSIP PTY LTD22,0004.3%14/02/201826/10/2021
OPTUS MOBILE PTY LIMITED12,0004.3%23/09/200823/09/2008
ADARGA PTY LTD11,0002.2%16/09/202516/09/2025
C2A INTERNET.COM.AU PTY. LTD.11,0002.2%13/07/202313/07/2023
CHECK TECHNOLOGY GROUP PTY LTD11,0002.2%31/01/202231/01/2022
CHIME COMMUNICATIONS PTY LTD11,0002.2%14/07/200414/07/2004
LMGPS LTD11,0002.2%23/11/202323/11/2023
NETERA PTY LTD11,0002.2%24/10/202524/10/2025
PIPE NETWORKS PTY LIMITED11,0002.2%24/09/201224/09/2012
PIVOTEL SATELLITE PTY LIMITED11,0002.2%16/04/202516/04/2025
THE TRUSTEE FOR READING FAMILY TRUST11,0002.2%21/10/201921/10/2019
VIRTUTEL PTY LTD11,0002.2%20/12/201520/12/2015
WHY PAY MORE 4 LESS PTY LTD11,0002.2%10/05/201810/05/2018

Number blocks registered for Derby

Every registered block for this area is allocated to a carrier. All 34 blocks, ascending:

Block startNumbersOriginal allocateeCurrent holderAllocatedTransferred
0851005000…1,000=VIRTUTEL PTY LTD20/12/2015—
0851034000…1,000=SOUL PATTINSON TELECOMMUNICATIONS PTY LIMITED14/07/2016—
0851063000…1,000=NETSIP PTY LTD14/02/2018—
0851092000…1,000=ADARGA PTY LTD16/09/2025—
0851121000…1,000=THE TRUSTEE FOR READING FAMILY TRUST21/10/2019—
0851155000…1,000=NETSIP PTY LTD26/10/2021—
0851156000…1,000=SYMBIO NETWORKS PTY LTD19/06/2020—
0851179000…1,000=WHY PAY MORE 4 LESS PTY LTD10/05/2018—
0851226000…1,000TWILIO AUSTRALIA PTY LTDSYMBIO NETWORKS PTY LTD24/09/202024/02/2021
0851286000…1,000=CHECK TECHNOLOGY GROUP PTY LTD31/01/2022—
0851317000…2,000=OPTUS NETWORKS PTY LIMITED19/05/2022—
0851324000…1,000=C2A INTERNET.COM.AU PTY. LTD.13/07/2023—
0851353000…1,000=LMGPS LTD23/11/2023—
0851383000…1,000=PIVOTEL SATELLITE PTY LIMITED16/04/2025—
0851412000…1,000=NETERA PTY LTD24/10/2025—
0851442000…1,000=SYMBIO NETWORKS PTY LTD19/08/2026—
0891020000…3,000IPTEL PTY LIMITEDSOUL PATTINSON TELECOMMUNICATIONS PTY LIMITED30/03/200001/12/2004
0891049000…1,000ENGIN PTY LIMITEDPRIMUS TELECOMMUNICATIONS PTY LIMITED24/12/200411/08/2015
0891152000…1,000=PRIMUS TELECOMMUNICATIONS PTY LIMITED21/07/2005—
0891183000…1,000=OPTUS NETWORKS PTY LIMITED16/06/2005—
0891211000…1,000GOTALK LIMITEDSYMBIO NETWORKS PTY LTD29/06/200526/08/2013
0891269000…1,000=SYMBIO NETWORKS PTY LTD24/04/2014—
0891328000…1,000=PRIMUS TELECOMMUNICATIONS PTY LIMITED03/02/2012—
0891373000…1,000=OPTUS NETWORKS PTY LIMITED25/07/2012—
0891377000…1,000IVOX PTY LTDSYMBIO NETWORKS PTY LTD18/06/201216/06/2014
0891382000…1,000=TELSTRA LIMITED20/05/2011—
0891458000…1,000AAPT LIMITEDPIPE NETWORKS PTY LIMITED24/09/201224/03/2026
0891565000…2,000=OPTUS MOBILE PTY LIMITED23/09/2008—
0891584000…1,000=TELSTRA LIMITED30/06/1991—
0891615000…5,000=TELSTRA LIMITED30/06/1991—
0891910000…3,000=TELSTRA LIMITED30/06/1991—
0891931000…3,000=TELSTRA LIMITED30/06/1991—
0891939000…1,000=TELSTRA LIMITED30/06/1991—
0891961000…1,000=CHIME COMMUNICATIONS PTY LTD14/07/2004—

Numbering areas next to Derby in the register

Immediately below and above Derby's blocks in the 0891… and 0851… prefixes sit Broome, Christmas Island, Cocos (Keeling) Island, Dampier, De Grey (Ext), Fitzroy Crossing, Great Sandy (Ext), Hall's Creek (WA), Karratha, Kununurra and Leopold (Ext).

Numbering areaFirst blockBlocksCarriers
Broome0851000000…4521
Christmas Island0851001000…3120
Cocos (Keeling) Island0851002000…3019
Dampier0851003000…3118
De Grey (Ext)0851004000…3118
Fitzroy Crossing0851006000…3118
Great Sandy (Ext)0851007000…2818
Hall's Creek (WA)0851008000…2817
Karratha0851009000…4620
Kununurra0851010000…3620
Leopold (Ext)0851011000…3018

Had a call from a Derby number?

No clear pattern in reports on these numbers yet. If a call worried you:

  1. Call back on a number you trust

    If a caller says they're your bank, the ATO, Services Australia, a courier or your telco, hang up and ring the organisation on the number from its website or your statement, never the number that called you. Caller ID can be faked.

  2. Report the call to Scamwatch

    The National Anti-Scam Centre uses Scamwatch reports to warn others and to get scam numbers blocked. Note the number, the time and what the caller claimed to be. If anyone is in danger, call 000.

    Report to Scamwatch ↗

  3. Register on the Do Not Call Register

    Registering landlines and mobiles is free and stops most telemarketing calls within 30 days. Charities, political parties, surveys and scammers aren't covered.

    Do Not Call Register ↗

  4. If you lost money or shared details

    Call your bank straight away on the number on your card and ask it to stop the payment. Then report it through ReportCyber, which passes cybercrime reports to the Western Australia Police Force. If your identity documents or passwords were shared, IDCARE's free support service can help you lock things down.

    ReportCyber ↗IDCARE ↗

Nationally, Scamwatch recorded $72.5 million lost to scams that started with a phone call in 2025 (down from $107.2 million), with a median loss of $3,800 per report that lost money, and phone-call scam reports are 73.7% below their 2021 level. Telcos blocked 109.3 million scam calls and 45.2 million scam texts in January to March 2026. Sources: Targeting scams 2025 (National Anti-Scam Centre); ACMA quarterly report, Jan–Mar 2026.

Derby numbers: questions and answers

Where is the Derby numbering area?

Derby is in Western Australia, in the Derby-West Kimberley council area. The nearest other numbering areas are Roebuck (Ext) (135 km), Broome (168 km) and Fitzroy Crossing (220 km).

What area code does Derby use?

Derby numbers use area code 08. Its register blocks start with 08 91 and 08 51. From overseas, drop the 0 and dial +61 8 followed by the eight-digit local number.

What time zone is Derby in?

Derby is on Australian Western Time (AWST, UTC+8), with no daylight saving.

Which carriers hold Derby phone numbers?

The ACMA register lists 18 carriers with allocated blocks in Derby. By allocated numbers the largest are Telstra (30.4%), Symbio Networks (13%) and Optus Networks (8.7%). A number can since have been ported to another provider.

When were Derby numbers first allocated?

The oldest block on record for Derby was allocated on 30 June 1991 and is held by Telstra; the newest on 19 August 2026, to Symbio Networks.

How do I report a scam call from a Derby number?

Report it to Scamwatch. If you lost money, call your bank first, then report it through ReportCyber, which passes it to the Western Australia Police Force. Unwanted sales calls go to the Do Not Call Register's complaint form (1300 792 958).

Check a number from Derby

Scammers spoof local landline numbers to look nearby. Guides: Australian area codes, how caller ID spoofing works.