Sim pack

You may be happy with your existing mobile phone, but not satisfied with the service you're receiving from your network or their call charges. By changing your existing SIM you automatically change networks without having to buy a new mobile.

Perhaps you are upgrading your mobile phone to a newer model? It's probably occurred to you that it would be a waste not to do something with your old mobile. By buying a Pay & Go SIM you get a new number so you can reactivate the old phone and give it to someone else in your family, or to a friend, so that they can make good use of it.

Or maybe you have recently arrived in the UK and you brought a mobile with you, you can benefit from great rates on O2 whilst you are here by purchasing an O2 Pay & Go SIM card and using it in your existing phone.

Pay & Go has no contract to sign and you only need to buy calltime when you want it so there are no monthly charges to worry about.

Before you buy your SIM pack you need to check a couple of things.

Did you sign a contract for your phone and receive monthly bills? You will need to refer to your contract to see if you are OK to switch and you may need to give notice to terminate your agreement. Usually, you're free to switch after 12 months.

Your existing network provider may prevent you from switching to the O2 network. They do this by locking your mobile on to their network. If this is the case, please call their customer service to get an unlock code. There may be conditions or a cost associated with this.

You need to check that your handset is compatible with O2's Pay & Go service. To be compatible your phone must either be a dual band, working on both 1800MHz and 900MHz frequencies or a 900MHz single band phone. If you are unsure whether the handset you wish to use is compatible, or whether it is locked to your network, just take it into any O2 store where they will be able to advise you. Once you've checked these points just buy the Pay & Go SIM pack that suits you, remove your old SIM from the back of your phone and replace it with our new one. Our SIM pack contains all the instructions you need. Choose the SIM pack to suit you O2 has three SIM packs to choose from:

• Choose from 2 great value tariffs - Talkalot and Original
• Save money with Bolt Ons including texts from 3p
• £2.50 free calltime when you register your details
• Available in O2 stores

• Choice of 2 tariffs- Talkalot and Original
• Low cost international calls and texts from 10p
• Save money with Bolt Ons including texts from 3p
• £5 calltime included upon activation plus an additional £2.50 when you register your details
• Available in London O2 stores

• Great value Online Talkalot tariff
• Top up £10 per month and get a free allowance, for example 300 text messages a month.
• Save money with Bolt Ons including 50% off calls & texts to 3 favourite numbers
• Available in O2 stores or buy online