Voicemail Number for O2
Voicemail Number for O2 — Quick Reference for Business & Personal Use
Need the voicemail number for O2 in a hurry? Below you will find the short-code, instructions for accessing your mailbox from any phone, and — if you run a business — a smarter alternative to standard O2 voicemail that most teams never consider.
O2 Voicemail Number
901
Dial 901 from your O2 handset to access voicemail. If calling from another phone, dial your own O2 mobile number and press * when the greeting plays.
The voicemail number for O2 is 901 on all O2 pay-monthly, pay-as-you-go, and business contract handsets. The same short-code works on O2-powered MVNOs such as giffgaff. Tesco Mobile — also on the O2 network — uses 222 instead.
How to Access O2 Voicemail From a Different Phone
There are times — particularly in a business setting — when you cannot reach your O2 handset but still need to retrieve messages. Here is how to check the voicemail number for O2 remotely:
- From any landline or mobile, dial your full O2 number (e.g. 07XXX XXXXXX).
- Wait for the voicemail greeting to begin playing.
- Press * (star) to interrupt the greeting.
- Enter your four-digit voicemail PIN when prompted.
- Follow the menu options to listen to, save, or delete messages.
Tip: If you have never set a PIN, O2 assigns a default. You can reset it by dialling 901 from your handset and following the PIN-change menu, or via the My O2 app.
O2 Voicemail Number vs Other UK Networks
For quick comparison, here are the voicemail short-codes for the UK's major networks:
| Network | Voicemail Number |
|---|---|
| O2 | 901 |
| EE | 150 |
| Vodafone | 121 |
| Three | 123 |
For full setup walkthroughs, PIN creation, greeting recording, and troubleshooting for O2 voicemail, see our comprehensive O2 voicemail guide.
Why Businesses Should Look Beyond the Standard Voicemail Number for O2
Dialling 901 is fine when you are checking personal messages, but for any business that relies on mobile calls — sales teams, field engineers, account managers — standard O2 voicemail introduces real problems:
- Single mailbox per SIM — there is no shared inbox, so if a colleague is off sick their messages sit unheard until they return.
- No transcription — you must dial 901 and listen to every recording in sequence, which wastes time during a busy working day.
- No email or CRM integration — voicemails are siloed on the handset and cannot be forwarded, logged, or searched.
- No intelligent routing — when a call goes unanswered it drops straight to voicemail instead of trying a colleague, a hunt group, or a reception desk.
How VoIP Replaces (and Improves on) O2 Voicemail for Business
A hosted VoIP or unified-communications platform sits alongside — or replaces — your O2 mobile contracts and gives your team enterprise-grade call handling without the enterprise price tag. Here is what changes:
| Feature | O2 Voicemail (901) | Hosted VoIP |
|---|---|---|
| Voicemail-to-email | ✗ | ✓ |
| Automatic transcription | ✗ | ✓ |
| Hunt groups / failover routing | ✗ | ✓ |
| Professional auto-attendant | ✗ | ✓ |
| Shared / departmental mailboxes | ✗ | ✓ |
| Works on mobile, desktop & desk phone | Mobile only | ✓ |
| Keep your existing O2 number | N/A | ✓ (via porting) |
Crucially, you do not have to abandon O2 to benefit. Many of our clients keep their O2 business mobiles for data and on-the-go calls while routing their main business number through a VoIP platform. Unanswered calls hit the VoIP voicemail — with transcription and email delivery — rather than the basic voicemail number for O2. The result is faster response times, fewer missed opportunities, and a far more professional impression on callers.
Can I Forward O2 Calls to a VoIP Voicemail Instead of 901?
Yes. O2 supports conditional call forwarding using standard GSM divert codes. You can redirect unanswered, busy, or unreachable calls to a VoIP number of your choice rather than allowing them to fall back to the default voicemail number for O2:
- Forward when unanswered:
**61*[VoIP number]#then press call. - Forward when busy:
**67*[VoIP number]#then press call. - Forward when unreachable:
**62*[VoIP number]#then press call. - Cancel all diverts (revert to 901):
##002#then press call.
This is a popular setup for small businesses that want to keep their O2 SIMs but gain the advanced voicemail, auto-attendant, and call-routing features that come with a hosted VoIP system. Our team can configure everything for you — there is nothing to install and no disruption to your existing O2 service.
Outgrowing the basic voicemail number for O2?
We compare every UK network and VoIP provider to find the right mobile and phone solution for your business — whether that means optimising your O2 contracts, adding hosted VoIP, or both. Free, no-obligation quotes.
Or call us on 0333 015 2615
Frequently Asked Questions
Is 901 the only voicemail number for O2?
For dialling from your own O2 handset, 901 is the only short-code you need. If you are calling from a landline or a different mobile network, dial your full O2 number instead and press * when the greeting plays to access the voicemail system.
Does it cost anything to dial 901 on O2?
Dialling the voicemail number for O2 (901) is included in your plan at no extra charge. However, if you access your voicemail while roaming abroad, standard roaming rates may apply depending on your tariff.
Can I use a VoIP system and keep my O2 mobile number?
Absolutely. You can either port your O2 number to a VoIP provider permanently or — more commonly for businesses — use conditional call forwarding to route unanswered calls from your O2 SIM to a VoIP voicemail. Both approaches let you keep the number your clients already know.
What if I have multiple O2 SIMs across my team?
Each SIM has its own 901 mailbox with no way to share messages between colleagues. A VoIP platform solves this by providing shared mailboxes, hunt groups, and centralised call management — meaning a missed call on one handset can ring the next available team member before ever reaching voicemail.
```