Whose number starts with 0400?
The 0400 mobile prefix appears in the ACMA register as held by TELSTRA LIMITED, which holds every one of the window's 1m allocated numbers. The earliest allocation in 0400 is dated 27 November 1998 (to ONE.TEL LIMITED, since transferred to TELSTRA LIMITED), the most recent 8 September 1999.
Source: ACMA register, data as of 16/10/2026
The story of 0400
The 0400 range carries one of the stranger stories in Australian numbering: the register still names One.Tel — the telco that collapsed spectacularly in 2001 — as the original allocatee, with Telstra recorded as the latest holder of the arcs. Numbers here have changed corporate hands without their owners ever noticing.
The 0400 ranges in the ACMA register
The 0400 window is covered by 3 allocations with a combined capacity of about 1m numbers, in the hands of 1 holder. Every range have changed hands since allocation: the register still names ONE.TEL LIMITED as original allocatee, with the latest transfer recorded on 7 June 2001.
| Range | Numbers | Original allocatee | Current holder | Allocated | Transferred |
|---|---|---|---|---|---|
| 0400000000–0400299999 | 300,000 | ONE.TEL LIMITED | TELSTRA LIMITED | 27/11/1998 | 07/06/2001 |
| 0400300000–0400799999 | 500,000 | ONE.TEL LIMITED | TELSTRA LIMITED | 08/09/1999 | 07/06/2001 |
| 0400800000–0400999999 | 200,000 | ONE.TEL LIMITED | TELSTRA LIMITED | 27/11/1998 | 07/06/2001 |
- 0400000000–0400299999 (300,000 numbers) was allocated on 27 November 1998 to ONE.TEL LIMITED and transferred on 7 June 2001 to TELSTRA LIMITED.
- 0400300000–0400799999 (500,000 numbers) was allocated on 8 September 1999 to ONE.TEL LIMITED and transferred on 7 June 2001 to TELSTRA LIMITED.
- 0400800000–0400999999 (200,000 numbers) was allocated on 27 November 1998 to ONE.TEL LIMITED and transferred on 7 June 2001 to TELSTRA LIMITED.
Telstra in 0400 and nationally
TELSTRA LIMITED holds 1m numbers in 0400 — the whole window — which is a small slice of its 78.8m mobile numbers nationally, or about 91% of every allocated Australian mobile number. The register places Telstra in 52 different 04xx prefixes, including 3 of the other nine in the 0400–0409 decade (0407, 0408, 0409).
| Holder | Numbers in 0400 | Share of 0400 | Share of all 04 numbers | Prefixes held |
|---|---|---|---|---|
| TELSTRA LIMITED | 1m | 100% | 91% | 52 |
The other prefixes in the 0400–0409 decade
Held by Optus Mobile, Vodafone Australia and Telstra: 0401, 0402, 0403, 0404, 0405, 0406, 0407, 0408, 0409. The decade's oldest allocation is in 0409 (10 March 1998, Telstra), its youngest in 0404 (25 August 2005, Vodafone Australia). Every allocated prefix in the decade has a single holder.
What does a call from a 0400 number mean?
A 0400 number is an ordinary mobile at ordinary rates. The register names the range holder, not the person calling — and with number porting the SIM may live on a different network entirely.
What people check and report about 0400 numbers
From searches typed into this site's lookup form since 3 September 2026, and the verdicts and moderated reports visitors left. A check usually follows a missed call.
No published reports for this prefix yet.
Had a call from a 0400 number?
No clear pattern in reports on these numbers yet. If a call worried you:
- 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.
- 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.
- 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.
- Forward spam texts to 0429 999 888
The ACMA collects unsolicited commercial texts forwarded to 0429 999 888 (standard message charges apply). Don't edit the message first. Scam texts that impersonate a bank, toll road or delivery company go to Scamwatch instead.
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.
0400 numbers: questions and answers
Which network does a 0400 number belong to?
The ACMA register lists Telstra as the holder of every allocated number in 0400 (1m numbers). Mobile numbers can be moved to another network, so the caller may now be with a different provider.
When was 0400 first allocated?
The earliest 0400 range in the register is dated 27 November 1998, to One.Tel; the most recent 8 September 1999. The window is covered by 3 register ranges.
How big is Telstra's share of Australian mobile numbers?
Across the whole 04 range, Telstra holds about 91% of allocated mobile numbers, spread over 52 of the 04xx prefixes.
How often are 0400 numbers checked?
People have checked 34 different 0400 numbers 35 times on this site since 3 September 2026, with no verdicts or reports yet.
How do I report a scam call or text from a 0400 number?
Report scam calls and texts to Scamwatch. Forward unsolicited commercial texts to the ACMA on 0429 999 888, and block the number from your phone's recent calls or messages. If you lost money, call your bank first, then report it through ReportCyber.
Check a 0400 number
Range data is not personal data and the number on your screen can be spoofed. Scam calls: Scamwatch. Guides: Who called me from this number?, Which carrier owns which mobile prefix?