Switching from T-Mobile to O2? It's a straightforward process to keep your existing phone number.

Step 1: Get a PAC Code from T-Mobile

If you’d like to move your phone number from T-Mobile to O2, the first step is getting your Porting Authorisation Code (or PAC Code) from T-Mobile.

There are two ways to get a PAC Code from T-Mobile:

  1. By Text Message: You can get a T-Mobile PAC Code sent to you via SMS text message. Text PAC to 65075 to receive a PAC Code from T-Mobile.
  2. By Phone: You can get a PAC Code by calling T-Mobile. To do this, call them on 150 using your T-Mobile handset. Alternatively, dial 020 7362 0200 from any other phone. You'll need to call during T-Mobile's opening hours (Monday-Friday 8am-8pm, Saturday 8am-6pm, Sunday 8am-6pm).

Here are some key things to know:

  • A PAC Code is 9 digits long and follows the format ABC 123 456.
  • Your PAC Code is valid for 30 days. If you don't use it during this time, the PAC Code will expire and you'll need to request a new one.
  • You shouldn't close your account at T-Mobile: it'll be closed automatically when your phone number is transferred to O2.

Don’t want to keep your T-Mobile phone number? You can switch to O2 without taking your phone number with you. If you'd like to do this, get a STAC Code from T-Mobile instead.

T-Mobile STAC Code (Leave T-Mobile Without Keeping Your Number)

If you’d like to leave T-Mobile without keeping your phone number, you’ll need to request a STAC Code rather than a PAC Code. There are two ways to get a STAC Code from T-Mobile:

  1. By Text Message: You can get a T-Mobile STAC Code sent to you via SMS text message. Text STAC to 75075 to receive a STAC Code from T-Mobile.
  2. By Phone: You can get a STAC Code by calling T-Mobile. Call them on 150 using your T-Mobile handset. Alternatively, dial 020 7362 0200 from any other phone. You'll need to call during T-Mobile's opening hours (Monday-Friday 8am-8pm, Saturday 8am-6pm, Sunday 8am-6pm).

Once you’ve gotten your STAC Code from T-Mobile, the rest of the process for joining O2 remains the same.

Step 2: Order your new phone or SIM card from O2's website

You should now order your new phone or SIM card using the O2 website. Please select the type of tariff you're intending to move to:

If you're looking for a SIM card from O2, the following deals from £8/month are currently most popular:

Network Data Monthly Cost
(will rise each April by RPI inflation plus 3.9%)
O2
  • Unlimited mins
  • Unlimited texts
40GB
data
£8.00
per month
12 month contract
See deal  
O2
  • Unlimited mins
  • Unlimited texts
60GB
data
£9.99
per month
12 month contract
See deal  
O2
  • Unlimited mins
  • Unlimited texts
Unlimited
data
£20.00
per month
24 month contract
See deal  

For a full list of available tariffs and the latest O2 deals, please refer to this page on O2's website.

Alternatively, if you're getting your O2 plan from a reseller, tap on their logo for more information:

O2 will assign you with a temporary phone number during the transition process. This will allow you to test out the service before you finally transfer your phone number to O2.

Step 3: Give the PAC Code to O2

Once your new phone or SIM card arrives from O2, switch it on and make sure everything's working properly. If, for whatever reason, you need to return or change the handset or SIM card, it's best to do this before transferring your phone number.

Once you're happy to continue with the phone number transfer, contact O2 and provide them with your PAC Code from T-Mobile.

Your PAC Code should be entered on O2's online form. You can also provide your PAC Code to O2 over the phone:

If you're joining O2 Pay Monthly, you can submit your PAC Code by calling 202 on your O2 handset. Alternatively, call 0344 8090202 from any other phone.

Alternatively, if you're joining O2 Pay As You Go, submit your PAC Code by calling 4445 (0344 8090222 if you're calling from another network).

If you have a STAC Code from T-Mobile rather than a PAC Code, this can be provided to O2 in the exact same way.

Providing your PAC Code to O2
The PAC Code should be submitted through a form on O2's website.

Remember:

  • You must provide the PAC Code to O2 within 30 days of it being issued by T-Mobile. If the PAC Code has already expired, you'll need to return to step 1 and request a new PAC Code from T-Mobile.
  • T-Mobile Pay As You Go customers: Try to use up your remaining credit as it can't be transferred to O2.

Step 4: Phone Number Transferred (Next Working Day)

Once you've provided a PAC code to O2, your phone number transfer will normally be scheduled for the next working day (Monday to Friday only, excluding English bank holidays).

On the day of the transfer, you'll momentarily lose coverage on both mobile networks. When this happens, restart your handset on O2. You should find that the O2 phone or SIM card will now associated with your original phone number.

  • If you see an error message (e.g. "SIM card registration failed"), this means it's time to restart your phone.
  • Once the phone number has been transferred to O2, your account on T-Mobile will automatically be closed. You'll receive a final bill from T-Mobile for any outstanding charges.

Get the Latest Deals from O2 →

Any Other Questions?

In case of any problems during the transfer of your phone number, you should contact your new mobile network (O2) with details of the problem.

If you have any other questions on using a PAC Code, please see my in-depth guide to transferring your phone number between networks. You can also read the comments below from other visitors to this website.

← Full Article: "PAC Codes - How to transfer your mobile number when switching networks"

Your Comments 1,966 so far

We'd love to hear your comments on transferring a phone number from T-Mobile to O2. The comments below are from people who've made the same transfer. You can add your own comments here.

To view all 1966 comments about transferring a phone number, please visit the main PAC Code article.

  • Tony balmer said:

    Using a HTC wildfire that was on T-mobile. I want to move to o2 but it’s asking for sim network unlock pin (8 numbers)?

    • Ken replied:

      Hi Tony,
      Thanks for your comment. You’re seeing this message about a “SIM Network Unlock PIN” as your HTC Wildfire is currently locked to T-Mobile. Before you’re able to use it on O2, you’ll first need to unlock it from T-Mobile. This will cost you £8.99. For more information, see my article on unlocking your smartphone. When unlocking your handset from T-Mobile, you’ll need to fill in the form here.
      Hope this helps,
      Ken

  • Steff said:

    I have been using my number with Tmobile for over 8 years and I still have the mates rate plan. My partner has recently bought me an IPhone which is locked to 02 so I have bought a PAYG sim to go into the phone and have asked Tmobile for my PAC code to change my number over. I would like to know if i get my iPhone unlocked to any network and want to switch back to Tmobile will I be able to still use the same number and will I still be on the same mates rates tariff or will I start a new connection from scratch?

    • Ken replied:

      Hi Steff,
      Thanks for your comment. If you’d like to stay on T-Mobile’s Mates Rates, you’ll need to keep the T-Moible account open. If you were to transfer your phone number from T-Mobile to O2, then it would close the account that’s open at T-Mobile and you would need to later sign up as a new customer on EE (T-Mobile is no longer available to new customers joining the network).
      If you simply want to unlock the handset from O2, you can do this with a free O2 Pay As You Go SIM card. There’s no need to actually keep the number assigned to the O2 SIM card: simply use it for unlocking then go back to your normal T-Mobile SIM.
      Hope this helps,
      Ken

  • David Mahon said:

    I switched my network from T-Mobile to O2 via CarPhone Warehouse on 19/11/14, receiving my PAC code on the 19/11 and thus made O2 aware of the pac code during the online transfer. Received my new O2 sim on 20/11 around midday switching sims and noticing my network had changed correctly to O2.

    However, today I have received a final bill from my original provider (T-mobile) for £238 as on the morning of the 20/11, I used my phone to make calls, emails, browse the internet and watch a couple of video’s. I was unaware that I would be charged for usage by T-Mobile on the 20th and was not made aware by T-Mobile that this could happen. What options are available to me, do I have any legal recourse as this is a bill I simply cannot afford.

    Thankyou for your replies as this is a deep concern to me.

    David.

    • Ken replied:

      Hi David,
      Thank you for your comment and sorry to hear about the problems you’ve experienced with T-Mobile. It is rather ridiculous they’ve charged you £238 for only half a day of usage: what’s their rationale for making such a charge? What tariff were you on when this happened? It would seem reasonable for them to charge a pro-rata rate for your final month of usage but there’s no way the final bill should come to £238. I’d certainly lodge a complaint with EE: hopefully this should help to get the bill revised as quickly as possible.
      Ken

  • E said:

    Hi Ken,
    Thanks for info here. I’m having a nightmare porting from T Mobile (EE) to O2. Port requested on Friday scheduled for Monday 6pm. Old number cut off on Friday so I have no means if my business customers getting hold of me on my kniwn number. Called O2 who are currently giving me the run around and no help whatsoever. They ofcourse are blaming T Mobile. Any advice you can offer would be gratefully appreciated. Thanks. E.

    • Ken replied:

      Hi E,
      Sorry to hear about the problems you’ve experienced transferring a phone number from T-Mobile to O2. Based on your description of the problem, the problem has occurred on the T-Mobile end (O2 are right in blaming T-Mobile). T-Mobile should keep your number active until the transfer actually happens: they shouldn’t disconnect it or end your contract early. A transfer through the PAC Code system should simultaneously close your T-Mobile account whilst moving the number over to O2. Hence, I’d recommend calling T-Mobile Customer Services (0845 412 5000) – they’ll be best placed to help in solving the problem.
      Good luck,
      Ken

  • Matthew Snook said:

    Hello

    My contract with Tmobile is up for 'renewal' on 18th Jan. I have just taken out a new contract with O2, to beat the VAT increase. Will it be possible to ask Tmobile for a PAC code now, and transfer to O2, or do I have to wait until the 18th Jan when my contract is up to renew? would they give a temp number for my existing contract? or disallow it?

    Hope you can help

    • Ken replied:

      Hi Matthew,

      Thanks for getting in touch. You should probably be able to ask them for a PAC Code now that you're in the final month. I suspect you'd have to pay for the rest of the month although you'll lose service once your number has moved over to O2. However, if you wanted them to switch the number you might be able to ask T-Mobile Customer Services to do that for you (let us know how you get on!)

      I think it's worth mentioning here that you don't save *any* money on your monthly tariff by taking your plan out now. You will only save money on the upfront cost of your handset. See my guide to VAT increases for more information.

      Ken

  • Sally said:

    Hi,
    i have recently transferred my sim only deal from tmobile to o2, now that the PAC code transfer has happened, my old tmobile sim is also still working! and yet i have the old number on the 02 sim too, is this a worry?
    Thanks

    • Ken replied:

      Hi Sally,

      Sounds like the number hasn't transferred over yet. Have you given your PAC Code to o2 and waited 2 days for the transfer to happen?

      Ken

  • Peter said:

    I have gave my Pac code into T-Mobile from O2 and it has been 3 days now and no switch over has occurred, can it normally take this long?

    • christina replied:

      t mobile arent the best when it comes to you requesting something with them ive been with them 2 years with 3 contracts and now changing to another network they are hopless get back on there case with it thats a terrible time to do that

Leave a Reply