Switching from T-Mobile to giffgaff? 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 giffgaff, 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 giffgaff.

Don’t want to keep your T-Mobile 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 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 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 T-Mobile.

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

If you have a STAC Code from T-Mobile 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 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 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 T-Mobile will automatically be closed. You'll receive a final bill from T-Mobile 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 T-Mobile 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.

  • Hi Ken,
    Apologies if this is stupid question or it has been asked before: my daughter has a Nokia phone on T-mobile monthly bundle – we want to get her a SIM Free Moto G and also transfer to a GiffGaff SIM so we can use their goodybags, which seem better.

    I can see that it is straightforward to get a PAC from T-Mobile to do this but my question is: what happens if we buy the Moto G from Three – which is cheapest route according to your report – do we have to transfer from T-Mobile to Three and then from Three to GiffGaff?

    If this is the case, would it be better to buy the phone SIM Free from somewhere else online?

    Many thanks,
    Alex

    • Hi Alex,
      Thanks for your comment. When purchasing the Moto G from Three, it’s provided to you on an unlocked basis. Hence, if you like, you can immediately use a SIM card from giffgaff inside the handset (there’s no need to actually use the Three SIM card). This way, you’re able to transfer your phone number directly from T-Mobile to giffgaff. If you’d like to use the SIM card from Three, then you can of course do a transfer from T-Mobile –> Three followed by another transfer from Three –> giffgaff.
      Hope this helps,
      Ken

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