Switching from O2 to giffgaff? It's a straightforward process to keep your existing phone number.

Step 1: Get a PAC Code from O2

If you’d like to move your phone number from O2 to giffgaff, the first step is getting your Porting Authorisation Code (or PAC Code) from O2.

There are three ways to get a PAC Code from O2:

  1. Online: You can get a PAC Code from O2 by logging in to the My O2 website. Once you've logged in, go to My details > Thinking of switching from O2?.
  2. By Text Message: You can get an O2 PAC Code sent to you via SMS text message. Text PAC to 65075 to receive a PAC Code from O2.
  3. By Phone: You can get a PAC Code by calling O2. To do this, call them on:
    • For O2 Pay Monthly, dial 202 (or 0344 8090202 from any other phone)
    • For O2 Pay As You Go, dial 4445 (or 0344 8090222 from any other phone)
    You'll need to call during O2's opening hours (Monday-Friday 8am-9pm, Saturday 8am-8pm, Sunday 8am-6pm).

Here are some key things to know:

  • The PAC Code from O2 should consist of six numbers with TEL at the start (e.g. TEL 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 O2: it'll be closed automatically when your phone number is transferred to giffgaff.

Still in contract with O2? If so, you may need to pay an early exit fee on your bill from O2. To find out how much this would be, text INFO to 85075.

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

O2 STAC Code (Leave O2 Without Keeping Your Number)

If you’d like to leave O2 without keeping your phone number, you’ll need to request a STAC Code rather than a PAC Code. There are three ways to get a STAC Code from O2:

  1. Online: You can get a STAC Code from O2 by logging in to the My O2 website. After logging in, go to My details > Thinking of switching from O2?.
  2. By Text Message: You can get an O2 STAC Code sent to you via SMS text message. Text STAC to 75075 to receive a STAC Code from O2.
  3. By Phone: You can get a STAC Code by calling O2. Call them on:
    • For O2 Pay Monthly, dial 202 (or 0344 8090202 from any other phone)
    • For O2 Pay As You Go, dial 4445 (or 0344 8090222 from any other phone)
    You'll need to call during O2's opening hours (Monday-Friday 8am-9pm, Saturday 8am-8pm, Sunday 8am-6pm).

Once you’ve gotten your STAC Code from O2, the rest of the process for joining giffgaff remains the same.

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

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

If you're looking for a SIM card from giffgaff, the following deals from £6/month are currently most popular:

NetworkMinutesTextsDataMonthly Cost
giffgaffUnlimitedUnlimited2GB£6.00
1 month
giffgaffUnlimitedUnlimited6GB£8.00
18 months
giffgaffUnlimitedUnlimited25GB£10.00
18 months
giffgaffUnlimitedUnlimited120GB£20.00
18 months
giffgaffUnlimitedUnlimitedUnlimited£25.00
18 months

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

giffgaff 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 giffgaff.

Step 3: Give the PAC Code to giffgaff

Once your new phone or SIM card arrives from giffgaff, 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 giffgaff and provide them with your PAC Code from O2.

Your PAC Code should be entered on giffgaff's online form.

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

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

Remember:

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

Step 4: Phone Number Transferred (Next Working Day)

As long as you've submitted your PAC Code to giffgaff before 3pm, your phone number transfer will normally be scheduled for the next working day (Monday to Friday only, excluding English bank holidays). After 3pm, you'll need to wait one extra working day for your number to be transferred.

On the day of the transfer, you'll momentarily lose coverage on both mobile networks. When this happens, restart your handset on giffgaff. You should find that the giffgaff 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 giffgaff, your account on O2 will automatically be closed. You'll receive a final bill from O2 for any outstanding charges.

Get the Latest Deals from giffgaff →

Any Other Questions?

In case of any problems during the transfer of your phone number, you should contact your new mobile network (giffgaff) 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 1,963 so far

We'd love to hear your comments on transferring a phone number from O2 to giffgaff. The comments below are from people who've made the same transfer. You can add your own comments here.

To view all 1963 comments about transferring a phone number, please visit the main PAC Code article.

  • I have a sim only contract with 02 but want to move networks to Giffgaff and keep my number, because I’m on contract with 02 can they refuse to give me my Pac code by law

    • Hi Craig,
      Many thanks for your comment. No, O2 isn’t allowed to refuse you a PAC Code – it’s your legal entitlement as described here. There would, however, be allowed to charge you an early exit fee if you end your contract early.
      Hope this helps,
      Ken

  • My contract with 02 runs out in a couple of weeks and I want to change to giffgaff. Do I have to wait until the last day of the contract in case I’m penalised or can I have it all set up now?

    • Hi Yvonne,
      Many thanks for your comment. You can leave O2 at any time to move to giffgaff, but it’s worth noting there’ll be a 30-day notice on you telling O2 you’d like to leave. You’ll pay an early termination fee if you leave during the 30-day notice period or of course, if you leave during the period of your original contract.
      For this reason, I’d probably try to call O2 a couple of weeks before you intend to leave. You can request a PAC Code from them, which has 30-days validity, so you can then comfortably move over to giffgaff whenever you’re ready.
      Hope this helps,
      Ken

  • HI Ken

    Great site. Many thanks for the clear and concise information. I’m going to buy a OnePlus2 phone and will transfer from 02 to Giffgaff. You have already provided very clear info so no need to repeat it for my sake (!).

    I’m going to buy a OnePlus2 smartphone. It looks great from a tech point of view and significantly cheaper than the mainstream phone manufacturers (Apple, Samsung, Etc).

    Any thought on this firm ?

    Kind Regards, Nick

    • Hi Nick,
      Thanks for your comment and glad the website was useful! Unfortunately, I haven’t had any direct experiences of the OnePlus2. I had a couple of friends using the OnePlus One (general feedback was it was OK) but not sure I know anyone with the OnePlus Two. Before you buy, I would however also look at some devices from Motorola and Huawei (they also offer good phones at a very competitive price).
      Ken

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