In this section, we’ll help you to change mobile network providers. We’ll also show you how to upgrade to the latest handset. Keep your old phone number & transfer your old data.

Have you decided to change either your mobile network or mobile handset? Whether it’s one or the other, this section of our website aims to help you out. For anyone changing network, we’ll show you how to keep an old phone number and also how you can unlock a smartphone for use on different networks. For those changing handset, we’ll show you how to get a new SIM card and also how to transfer your data to a brand new device.

Please select an article to begin reading more:

PAC Codes: Transfer Your Mobile Number To A New Network

How to transfer & keep your phone number when switching to another mobile network: a step-by-step guide to using a PAC Code.

Unlocked Smartphones: Network Policies, How To Unlock & Where To Buy

Everything you need to know about mobile unlocking. Find out which networks lock their phones, how to unlock your handset and where to buy a new unlocked smartphone.

How to replace your SIM Card with a Micro SIM or Nano SIM

Newer handsets typically require a Micro SIM or Nano SIM. Therefore, if you're changing handsets, you may also need to change the size of your SIM card at the same time.

Cancelling Your Mobile Phone Contract: Exit Fees & Notice Periods

Find out how to cancel your mobile phone contract, including how much notice you need to give and any exit fees that might apply.

How To Use Up Your Remaining Pay As You Go Credit

Find out how to use up your remaining Pay As You Go credit when moving to another network.

Giving Your Old Phone To Someone Else: Step-By-Step Checklist

You can give your old mobile phone to someone else, like a friend or family member, when upgrading to a newer handset.

Mobile Internet APN Settings For UK Networks: Setup Mobile Data & MMS

After inserting a SIM card from a new network, you'll sometimes need to configure your mobile internet APN settings before you can get online.

Your Comments 15 so far

We'd love to hear your thoughts and any questions you may have. So far, we've received 15 comments from readers. You can add your own comment here.

  • Shirley R ea said:

    I am anxiously awaiting your review of the G6 range of Motorola mobile phones. Hope it will be available soon. I buy nothing until you have pronounced. Many thanks for a great site.

  • I wondered if you could help me I purchased an iPhone 6s directly from last year I’m wondering if I can use a Sim card I purchase in Japan when I go there next year.
    I know the phone is unlocked but I don’t know if it internationaly unlocked can you help? thank you

    • Hi Mark,
      Yes – the great news is your iPhone is also unlocked for use internationally. You can use it abroad in other countries with a different SIM card without issue.

      • Thank you this has really helped this will save me a fortune when I have to just open Google maps
        Because data costs are insane for visiting Japan.. 🙂

  • Hi Ken
    Thank you for your very informative & interesting site.
    I have recently had to leave Tesco Mobile as the service this year has deteriorated a lot (no signal for 3 months of the year!) and have switched to Asda pay as you go as their tariff is really good, but was disappointed to find out I cannot send short code texts. I now find that a lot of networks don’t allow you to do this. Can you recommend a reasonably priced network that does allow you to send 5 digit texts?

    • Hi Jenny,
      Thanks for your comment. Unfortunately, I couldn’t give you any specific advice about five-digit short codes (I’m not sure whether there’s a list of which mobile networks support this functionality?). I suppose my first suggestion is to see if you can find an alternative number (e.g. is there a regular landline or mobile number you could text instead?). If not, it might be the case you’ll need to go with one of the major networks who’ll probably be more likely to support this functionality.

  • Hi ken
    thanks for all the info on mobile phones its one of the best I have seen on line I have just joined ee mobile on pay as you go. do I have to use the mobile within 6months or I will loose my number and money on the account
    thanks for your help
    john sanger

  • I’m in Spain on holiday and my orange htc phone has died. Can’t get it to charge or anything. We were due to go home tomorrow but my husband’s had a heart attack and we won’t be able to fly for another 3 weeks. If I buy an Orange phone in Spain can I put my UK Orange SIM into it.

    • Hi Pat,
      Very sorry to hear of the situation: wishing you both all the best & hoping your husband will get well soon.
      In response to your question: if you buy a locked smartphone from any of the Spanish networks, it will only work on that specific Spanish network. So an Orange Spain phone will not accept Orange UK SIM cards. The same goes for Vodafone Spain handsets (they will not accept Vodafone UK SIM cards). Your only real option for buying a phone is Spain is probably to buy one that’s SIM-free/unlocked (try the Phone Warehouse, which is the Spanish equivalent of the Carphone Warehouse).

  • Hello ken thanks for this site Very informative and easy to follow, will bookmark and spread the word…..
    Question; do they have a legal requirement to give a pac code if the phone is disconnected ?

    • Hi Shell,
      Thanks for the comment. Unfortunately, this is one situation not covered by the PAC Code system. If your phone line has already been disconnected, the number will have normally been lost and would have hence been returned to your mobile phone network. Unfortunately, if this has already happened, it would mean there’s no way of getting your number back. As a small lifeline, rather than disconnecting you, some networks will change your account to one on Pay As You Go. It’s also worth contacting your old network to see whether the phone number is still available to you (e.g. it may have been frozen).

  • HI there
    My upgrade is due from O2, I want to take up the upgrade and send the phone to my friend in the USA. Please can you tell me if an at&t sim will work in the phone?

    • Hi PD32,
      Your O2 handset should work on AT&T USA’s 3G network providing it’s unlocked and providing it supports quad-band 3G (this should be true of most smartphones being sold today). If you’d like to check specifically for your handset, check the spec sheet for 3G support at 850MHz or 1900MHz. For AT&T’s 4G network, it’ll need to support band 17 (LTE at the 700MHz frequency).
      Hope this helps,

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