Switching your mobile phone handset, network or tariff - 3/3

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So you've decided you want a better deal on your mobile phone tariff and are ready to make the switch. How do you go about it? In part three of the moneysupermarket.com guide we aim to show you the way.

Mobile phone basics: using your current SIM card

The reasons for retaining your current SIM card are obvious - it contains your mobile phone number, your subscription information, your address book, etc. Removing your SIM card from one phone to another will, in effect, transfer your number and bills from one handset to another.

However, it's not that simple. Some networks have different frequencies that are not compatible - O2 and Vodafone mostly operate on 900MHz while Orange and T-Mobile use 1800MHz. Additionally, some networks put software into their phones to stop you using another network's SIM. This SIM lock can be removed with a release code - but there is usually a £20-£35 fee for this service and some phones simply won't accept any other SIM card.

Mobile phone basics: making the switch

The first part of the switching process is to go to the price comparison tool at moneysupermarket.com. This will compare handsets, tariffs and services across networks in direct relation to your requirements. Moneysupermarket.com will help you find the best mobile phone deal at the right price.

Once you have decided on the network you wish to move to, go to your existing provider and tell it you want to switch. Remember to keep your number active if you wish to retain it with your new network.

Ask your current provider for a nine digit Porting Authorising Code (PAC), which has to be given to your new provider. This is valid for 30 days. After a credit check, and the settling of any outstanding bills, you will be given a date of transfer of your number and a new SIM card and phone if this is part of the deal. This process should take about five days. You might have to pay a fee for the transfer paperwork.

A PAC is valid for 30 days and if you haven't used it by the end of the period you would have to contact your original provider for a new one. Transfers take three-ten days and during this period your account must remain active. Do not cancel the old account before attempting to move your number.

Remember to use moneysupermarket.com to get the best mobile phone deal available. Our price comparison tool will not only find you the cheapest mobile phone available for your needs, but will also include features and services to make sure you get exactly what you need.

So if you're thinking of making the switch, use moneysupermarket.com to be sure you're making the right move.