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Mobile Support and Training

Getting Started

Gamma Mobile service is built exclusively for the UK business market; designed to deliver improved coverage for voice and data via your device that empowers, not hinders, conducting business while on the move.

  • Great population coverage

    99% outdoor and 98% indoor

  • Call and text with WiFi

    Stay connected in areas with no signal

  • Network investment

    Over £2 billion is being invested in the network to continue to improve reliability, speed and call quality.

  • 5G spectrum

    With three times more 5G spectrum than any other UK network, to fully exploit the benefits of increased speeds, higher capacity and reduced latency.

Getting started...

Getting starting with a new number

  • If you do not have a pre-arranged activation date please call 0333 014 0333 to activate your service.
  • Your service will be live within 2 hours of activation. Push the SIM out from the holder.
  • Insert the SIM into your phone, then you’re good to go.

Getting starting with an existing number

  • A date to transfer your existing mobile number will have been arranged
  • On your arranged transfer day push the SIM out from the holder
  • Insert the SIM into your phone making sure you have both old and new SIM cards with you on the day.

Transferring an existing number

When will the transfer take place?

How will I know when I have been disconnected from my old network?

How will I know when my number has been transferred?

Do I need to be in the UK to transfer my number?

Voicemail and call forwarding

The voicemail service will be set up automatically when your SIM card is activated.

The first time you call into your voicemail you will be asked to set up your PIN and record your name.

Information about the voicemail structure can be found here.

To access voicemail call 07782333123 or use the short code 121 from your device

As standard all unanswered calls, and calls when you are busy or unreachable, are diverted to voicemail. Call forwarding to an alternative phone number can be added from your device settings menu or by calling the shortcodes.

Forward calls conditionally:
when busy, unanswered and out of reach

To set up
**004*[phone number]#

To switch off
#004#

To re-activate and forward to the same number as before
*004#

Forward calls unconditionally
Your device will not ring.

To set up
**21*[phone number]#

To switch off
#21#

To re-activate and forward to the same number as before
*21#

Troubleshooting FAQ

My device says emergency calls only

I have been asked for a PIN code for my SIM

I have blocked my SIM card how do I unblock it?

I didn’t receive my network settings

What is the voicemail number to call?

I can’t connect to the internet on my phone

How do I find my phone details?

My phone is lost or stolen

My device is not working with my new SIM

Useful contact details

Customer Services
0333 014 0333

Lost or stolen phone
0333 014 0333 (option 3)
Available 24×7

Faults
0333 014 0333 (option 3)

Provisioning queries
0333 014 0333 (option 3)
horizonmobileorders@gamma.co.uk
Monday to Friday 0900 – 1700hrs