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How do I change mobile network?

Some people are intimidated by the idea of switching mobile network. They think that they’ll be without service for weeks or that they’ll need to change their mobile number losing their old one. In actual fact, the process is very quick and easy and you can keep your old number. You shouldn’t experience any downtime at all and porting your number should only take a single business day.

First things first

Before you switch network, you need to be sure you want to change as well as decide which network you want to change to. It’s a good idea to read reviews before you make a decision as the price, customer service and available feature will all affect your decision. You should also understand the difference between a mobile network and virtual network. Even cheap normal mobile network operators like 3 are often more expensive than virtual operators such as Giffgaff. As well as checking reviews of your new network, you should also look into the coverage in your area. Although all mobile networks cover 99% of the UK, some will provide better mobile signal in places you commonly use you phone (like home and work) than others. Also, be aware that 3G coverage coverage varies quite a lot too so if you use the internet on your phone check whether you’ll be able to get a strong signal for fast data usage.

Keeping your mobile number

Once you’ve decided on the network you want to change to, if you want to keep your existing mobile number you’ll need to get your PAC code from your existing operator. To help you do this, we have an article describing how to get your PAC code and a letter template in case you’re having difficulties.

Usually getting your PAC is as simple as calling up your mobile network and asking for it. They should either give it to you immediately or text it to you within a couple of hours.

Choosing a new network and getting a new SIM

Firstly, you obviously have to carefully choose which network you want to change to. Of course, with so many choices, this can be rather confusing. Which is why we’ve handily reviewed all the UK mobile networks and included a summary of their pricing as well as a detailed analysis of their coverage, customer service and the various special offers and bundles that are available.

We’ve also created the most detailed price comparison available which will help you see which tariff on which network will be best for you as well as researched the network coverage of every network.

Once you’ve decided which network will be the best match for you, you need to get a new SIM card. There is no way to change networks and keep your old SIM but don’t worry – you can still keep your old mobile number. To get your SIM, either go to the review page for your chosen network or look on our list of free SIM card links – you can order a new SIM card online and it will be delivered quickly to you at home.

Backing up

Before you chuck away your old SIM make sure you backup any information that might have been stored on it. Typically most data is saved on your phone not your SIM so this is unnecessary but do check that important contacts and messages are not on your old SIM card before throwing it away.

The switchover

Once you’ve got your new SIM and your PAC you’re ready to change. Phew! First, activate your new SIM – you usually do this by making a £10 top-up (some networks such as Giffgaff give you free credit when you activate). Contact your new network and give them your PAC – they should book you in for a mobile number port (this will usually be the next working day). Then, when the day arrives, sit back and relax as your new network does all the hard work for you.

Keep your old SIM in your phone to start with. You will experience a loss of service at some stage depending on when your old service provider releases your number. The error message on your screen should say something like “SIM card registration failed”. You can now put your new SIM into your mobile. Then just switch your mobile off and on again – this causes the network search to start and you’ll soon find that your new SIM is fully activated with your old number transferred in. Congratulations!

by Jon M

43 Responses to “How do I change mobile network?”

  1. Georgia 19 July 2016 at 09:03 Permalink

    Hi, I’m struggling to find out whether or not I will receive the texts that my number had been sent in the 2-3 days my number was ‘inactive’ before being ported from Vodafone to o2?

  2. NATASHA 15 March 2016 at 16:06 Permalink

    I want to try giffgaff,how do I go abaut it?

    • Francis White 18 March 2016 at 20:05 Permalink

      Giffgaff have just increased their call charges from 10p pm to 15p pm

  3. Fiona 18 December 2015 at 13:24 Permalink

    What happens with a phone number for the phone switched *from*? Does it have no number ie not usable if need a reply on a call, or another number- but where would I find that please?

  4. gita 10 December 2015 at 07:32 Permalink

    i have spare iPhone 4(locked to O2) which i want to give my sister.My brother got a virgin sim micro sim for her,how do i switch,so she can start using before xmas!

  5. Huma 19 September 2015 at 21:53 Permalink

    I wish to change from EE to Vodaphone on a 12 month sim only contract. I have had to give EE 30 days notice which expires on 6 Oct. I have obtained a PAC no. to keep the same tel. no. My question is if I go on a 12 month contract with Vodaphone, should I get the sim now or wait until nearer 6 Oct. Does the Pay Monthly contract start once I activate the sim or when I make the purchase?

  6. J w 11 July 2015 at 22:53 Permalink

    Hi. I have a phone that had a gif gaff SIM card. I recently purchased a tesco mobile SIM card in order to change networks. I managed to put £10 onto this SIM card online after swapping the SIM cards in the phone. Tesco have a record of the £ 10 purchase but I am now unable to use the phone as I can only activate the sim by receiving a text and i have not yet got one. After contacting tesco mobile they tell me that the credit has gone to old orange number that used to be allocated to the phone pre gif gaff and that the phone must be locked by orange. I don’t understand why we have been using a gif gaff sim with no problems if the phone is locked by orange.

  7. Clara 24 June 2015 at 21:51 Permalink

    Yesterday I upgraded from a samsung to an iphone 6. I also changed my network from EE to Vodafone. EE gave me my pac number and said that when my iphone had got signal which it would have in 24 hours then I should ring vodafone and give them my pac number so i can keep my old number. However, my iphone did not get signal within 24 hours but i went into vodafone anyway and gave them my pac number, temp number and old number and they said my iphone will activate within 48 hours. Will it still activate despite the signal not having come through before I gave them my pac number?

    • Mobile Network Comparison 24 June 2015 at 23:47 Permalink

      That shouldn’t be a problem but there’s no issue with giving Vodafone your PAC immediately. Let us know how you get on.

      • Clara 25 June 2015 at 20:50 Permalink

        Hi. My iphone is now working with my old number which is great. However, on my iphone contact list at the top where it tells me what my number is, it still has the temp number even though I have been sending/receiving texts and calls and it is working with my old number. Also, my old phone still has signal. Could this be because it is still updating the whole process?

  8. Frank James 18 June 2015 at 06:01 Permalink

    I have bought a new iPhone 5c through an online company & chosen EE as the network provider for that mobile. My old iPhone 4 is also with EE. I have been given my PAC number from EE for my old iPhone. When my new iPhone 5c arrives with its new mobile number will I have any difficulties in porting my old mobile number from EE to my new IPhone 5c which is also going to be with EE : I.e. Presumably it is possible to port a number with the same network provider

  9. Gus Smith 8 June 2014 at 21:30 Permalink

    I am trying to change from Orange to 3, I obtained a pac code from orange but 3 but when I use the code and get it processed 3 say that my mobile number is invalid. What do I do do now orange say the pac code is correct,and 3 say they can not move my number.

  10. ALI QAISER GHORI 10 April 2014 at 15:44 Permalink


  11. Lis 18 July 2013 at 19:35 Permalink

    I have a PAYG phone with Three and want to transfer the number to a different PAYG phone with Orange (much better signal). I haven’t asked for a PAC code yet as I need to minimise missing calls for my work. When will the Three service go dead – is it when they give me the code or is it when I pass it on to Orange? And is it quicker if I pass it on over the Orange website, by phone or in an Orange shop? Any advice?

    • Mobile Network Comparison 18 July 2013 at 19:43 Permalink

      It won’t be until after you pass it on to Orange. It really depends how they do number ports about the quickest way. The actual process will only take a few hours, it’s whether their procedures can let you pick a certain date or even let you know the date it will be processed. Probably best to go in a store to ask. At least some networks let you pick the date it will go through.

  12. Charlotte R 16 June 2013 at 20:07 Permalink

    I have bought a new phone and contract through Orange (EE) and was told that the switch over between my old phone on Virgin, and the new phone would happen over the next two days. It didn’t. My contract with Virgin runs out tomorrow and I think that I am going to be left with no phone. The man in the shop took my PAC code and said that he would get it transferred and that the changeover would happen automatically Friday/Saturday morning. So far, it has not. What can I do?

  13. Anne 19 June 2012 at 22:08 Permalink

    Hi, I want to change my phone network because my friend Elizabeth has unlimited texts. Also, I would like to complain about airline food. And those peanut bags. who are they trying to keep out of those things!? Also, my name isn’t Rebecca Parker or Mill.

  14. richy rich 18 April 2012 at 03:19 Permalink

    i have bought an iphone 4s second hand that is locked to Vodafone , I want to change the network to O2 as all my family is on it

    I phoned up Vodafone a few days ago an the lovely lady took my imei number( or whatever it’s called ) down an my email addy and said that the code would come through from apple in a few days to change the network , great I thought that was easy…..

    today I phoned up again as code still not sent to addy , and the gentleman told me I needed a Vodafone sim or micro sim with £20 top up on it to carry out the code being sent out to me ???? I mentioned to him that the last I phoned up the woman said it had been sent , he then said that this did not go through as I needed a phone number from Vodafone to act like an account number ??? wtf ???
    anyone else had this ? and more importantly ….. can anyone throw any light on if I can get it done for free through Vodafone ?

  15. Kia 11 March 2012 at 12:20 Permalink

    I have an iPhone 3Gs on O2 at the moment and data coverage is AWFUL. I’d like to switch and from your reviews it looks like 3 might offer the best data coverage/usage. But I don’t fancy paying £30 a month for 24 months (£720) for an iPhone 4 when Tesco offers the same for 12 months (£360 plus handset price which will still be less than £550 in total)…but Tesco uses O2 network! Aaargh!
    What to do???

    • Mobile Network Comparison 12 March 2012 at 13:31 Permalink

      Have you done the calculations for a SIM-free iPhone?

      Also, what’s your monthly usage? Bear in mind how much more you get with 3 on The One Plan.

      • Kia 15 March 2012 at 10:51 Permalink

        I have read the above article, but I didn’t quite understand… Giffgaff have the deal where you pay £499 for iPhone4S 16MB but then you have to keep paying £10 a month? Is that supposed to be SIM free? My usage is minimal, I just want a network with good data coverage, so with that I would obviously like as unlimited data as possible, minutes and texts are not so important.

  16. nic 6 March 2012 at 14:27 Permalink

    ok thanks i will give it ago

  17. nic 6 March 2012 at 13:58 Permalink

    hi i have a htc desire s phone its on 3net work i have a spare virgin sim hoe can i change it over to virgin.

    • Mobile Network Comparison 6 March 2012 at 14:00 Permalink

      Just call up 3 to get your PAC code and then give it to Virgin Mobile and they’ll do all the work and switch it over for you. If you have any other questions, just browse the site or ask us 🙂

  18. JonJOE 5 March 2012 at 20:37 Permalink

    Hey, what if the switching is happening on Tuesday for example and you don’t switch on your phone on for a week or 2 after the porting date. Will the porting fail?

  19. Philip 10 February 2012 at 11:10 Permalink

    I want to change my existing phone and provider (Orange & Sony Ericsson) buying an iphone and using GiffGaff. Would I still be able to keep my existing number? I think the sim cards for both would be different? How would i go about it?

    Cheers in advance

    • Mobile Network Comparison 10 February 2012 at 11:18 Permalink

      Yes you’ll be able to easily keep your phone number but you will also have to change SIM card. Simply order your Giffgaff SIM and activate it online. Then go to our port number page and start off by ordering your PAC from Orange. Then you can switch your number over and close your Orange account and only need to use your Giffgaff SIM with the same number.

      Let us know if you have any other questions.

  20. Ian Martin 5 November 2011 at 11:53 Permalink

    Hi in the section headed “The Switchover” right at the end you say “this causes the network search to start and you’ll soon find that your new SIM is fully activated with your NEW NUMBER too. I thought you kept your old number?

  21. AlanS 28 September 2011 at 12:53 Permalink

    How long before I ‘port’ is it OK to get the PAC code….?
    Days, weeks…??

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