Help and Support


Can I use the Sim4Business SIM card on all phones?

Our service works with the vast majority of mobile phones but you must make sure that your mobile phone is unlocked.  You can check if your phone is unlocked by inserting another SIM from a different network provider into your phone.  If it works normally and displays the name of a mobile network, eg. O2, your phone is unlocked and ready for our Sim4Business SIM card.

Phone unlocking

When you put the Sim4Business SIM card into your phone and you get one of the following messages, your phone is probably locked:
• "Insert SIM"
• "Enter subsidy code"
• "Phone restricted"
• "SIM not valid"
• "SIM not accepted"
• "SIM locked"
• "Wrong SIM"
• "Network locked"
If your phone is locked it’s easy to unlock it online, at a local mobile phone shop or by speaking to your network operator to obtain the unlocking code.

Where is my new number?

Your new mobile number and pin number are printed on the card which is attached to the SIM.  Please keep your SIM card holder for future reference.

Are my contacts stored on the phone or on the SIM?

Check if your contact numbers are saved on to your phone by inserting your Sim4Business SIM. If you can see your contacts, your phone is ready for use. If your contact numbers are not available, then place your UK SIM back into the phone and copy your contacts from that SIM onto the phone.
We recommend that you update your numbers to include 0044 so you can call back to the UK. Make sure you take off the first 0 on the UK number then add 0044 eg. 0208 203 123456 would become 0044 208 203 123456.

Can I send text messages?

The Sim4Business SIM card allows you to send/receive texts.  Text messages received on your Sim4Business UK mobile number will be free of charge.

When sending texts make sure you key in the full country code and destination number.  Prices for sending SMS can be found here – Rates Calculator

How do I make a call/text?

Sim4Business uses a process known as a Call back.  This means your phone calls you back once you have dialled the number you wish to call/text.  To make a call or send a text:

Dial country code and number (even when in the same country) and press the send/call button.

For example:  0044208203123456 send/call

There will be a short pause, with no sound or line tone.  Your phone may (depending on handset model) display an on screen message saying “Thank you for using the service.  Your call will be connected soon.”

After a few seconds, your handset will ring and when you answer you will hear a voice message saying “Please wait while we connect your call”.  You will then hear a normal ring tone and you will be connected to the number you dialled.  When finished, please hang up as you would normally.

SIM reset and network selection

If you are experiencing service issues we suggest that you perform a SIM reset and manual network selection.  This does not affect your personal phone settings or phone contacts.

1. With your phone switched on, remove the battery, then the SIM card.
2. Replace the battery without the SIM card.
3. Turn your phone on.
4. Your phone may display an Insert Sim message.
5. Wait 15 seconds and turn your phone off.
6. Remove the battery and replace the SIM and battery.
7. Turn your phone back on.

Manual network selection

In addition to a SIM reset, we suggest you try to manually select an alternative network.  Please refer to your phone instructions for the location of this option.

Don’t forget to set your Network Selection option back to Automatic when you travel to a new country.

How do I top-up?

We offer a top-up service on our website so you will never be left without credit on your Sim4Business SIM.  Instructions for adding credit to your SIM can be found here – Top-Up

How do I dial a short code?

Your Sim4Business SIM card is pre-programmed with two short codes (3 digit numbers) enabling you to connect to the services directly.

* 803 Check balance (you will receive an SMS to your mobile)

* 121 Voicemail

To dial enter the 3 digit number and press send/call.