Switching from Three to BT Mobile? It's a straightforward process to keep your existing phone number.

Step 1: Get a PAC Code from Three

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

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

  1. Online: You can get a PAC Code from Three by logging in to the My3 Account website.
  2. By Text Message: You can get a Three PAC Code sent to you via SMS text message. Text PAC followed by your date of birth in DDMMYY format to 65075 to receive a PAC Code from Three.
  3. By Phone: You can get a PAC Code by calling Three. To do this, call them on 333 using your Three handset. Alternatively, dial 0333 338 1001 from any other phone. You'll need to call during Three's opening hours (Monday-Friday 8am-8pm, Saturday 9am-6pm, Sunday 9am-6pm).

Here are some key things to know:

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

Still in contract with Three? If so, you may need to pay an early exit fee on your bill from Three. To find out how much this would be, text INFO followed by your date of birth in DDMMYY format to 85075.

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

Three STAC Code (Leave Three Without Keeping Your Number)

If you’d like to leave Three 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 Three:

  1. Online: You can get a STAC Code from Three by logging in to the My3 Account website.
  2. By Text Message: You can get a Three STAC Code sent to you via SMS text message. Text STAC followed by your date of birth in DDMMYY format to 75075 to receive a STAC Code from Three.
  3. By Phone: You can get a STAC Code by calling Three. Call them on 333 using your Three handset. Alternatively, dial 0333 338 1001 from any other phone. You'll need to call during Three's opening hours (Monday-Friday 8am-8pm, Saturday 9am-6pm, Sunday 9am-6pm).

Once you’ve gotten your STAC Code from Three, the rest of the process for joining BT Mobile remains the same.

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

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

If you're looking for a SIM card from BT Mobile, the following deals are currently most popular:

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No price plans could be found matching this criteria.

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

BT Mobile 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 BT Mobile.

Step 3: Give the PAC Code to BT Mobile

Once your new phone or SIM card arrives from BT Mobile, 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 BT Mobile and provide them with your PAC Code from Three.

Your PAC Code should be entered on BT Mobile's online form. Alternatively, you can give the PAC Code to BT Mobile by calling 150 on your BT Mobile handset. You can also call 0800 800 150 from any other phone.

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

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

Remember:

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

Step 4: Phone Number Transferred (Next Working Day)

As long as you've submitted your PAC Code to BT Mobile 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 BT Mobile. You should find that the BT Mobile 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 BT Mobile, your account on Three will automatically be closed. You'll receive a final bill from Three for any outstanding charges.

Get the Latest Deals from BT Mobile →

Any Other Questions?

In case of any problems during the transfer of your phone number, you should contact your new mobile network (BT Mobile) 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 Three to BT Mobile. 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.

  • Hi Ken, I transferred with a PAC code to BT from Three a few days ago. BT messed up and accidentally deactivated my phone number. I am still within the cooling off period and after the experience of their customer service would like to get another PAC code and transfer back (as I gather the original transfer cannot be recalled) but BT are saying this can’t be done unless my phone is reactivated, which takes a few working days and so might take me beyond the cooling off period of 14 days. Do I have any options other than to wait and try? Is there a way to cancel my contract with BT now and then force them to let me transfer it out?

    • Hi James,
      Sorry to hear about the issues you faced transferring a phone number from Three to BT Mobile. Have they told you whether they’re able to recover your original phone number? I’d have thought that things should be fine as long as long as you tell BT you want to cancel the contract during the cooling-off period (if it takes extra time for them to amend their mistakes, this is something they should be liable for and it shouldn’t prevent you from being able to exercise your rights to cancel).
      Ken

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