Last Updated: 29th July 2025
Are you thinking about leaving Tesco Mobile and switching to Three? Then you're in the right place! Switching networks and keeping your number in 2025 is simple and easy thanks to Ofcom's policy changes.
We've put together a quick and easy to use switching guide. Our guides allow you to select the network you wish to switch to and from, and you will be given a step by step guide on how to keep your number and move to a new SIM Only Deal.
It is worth noting that if you wish to join Three and get a new number then you can use a STAC code in order to get a new number and will cancel your existing contract.
Joining Three and leaving Tesco Mobile
Select which network you would like to switch from and to and we will give you precise instructions on how to keep your number when switching to a new SIM Only Deal. Show Quick Links
- Transfer your number from 1pMobile to Three
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- Transfer your number from EE to Three
- Transfer your number from Giffgaff to Three
- Transfer your number from Honest Mobile to Three
- Transfer your number from iD Mobile to Three
- Transfer your number from Lebara to Three
- Transfer your number from Lycamobile to Three
- Transfer your number from O2 to Three
- Transfer your number from Sky Mobile to Three
- Transfer your number from Smarty to Three
- Transfer your number from Spusu to Three
- Transfer your number from Talk Home to Three
- Transfer your number from Talkmobile to Three
- Transfer your number from Tesco Mobile to Three
- Transfer your number from Vodafone to Three
- Transfer your number from Voxi to Three
Joining Three and transferring your number from Tesco Mobile is a simple process and usually takes no longer than 1-2 working days.
The process which will go through in more detail below involves requesting a PAC code from Tesco Mobile and handing it to Three.
You can either hand the PAC code over to Three during the ordering process or after you have received your new SIM card or eSIM has been activated.
1. Request a PAC code from Tesco Mobile
Switching from Tesco Mobile is quick and easy. You even get to keep your current number! There is no need to memorise a brand new phone number or update all your contacts.
Here is how the switching process works:
- Text: From your Tesco Mobile number, text PAC to 65075 for free. This is a universal number created by Ofcom to make the switching process easier. You will receive a reply within 2 minutes containing your PAC code.
- Online: Contact Tesco Mobile via the online live chat service and request a PAC code.
- Phone: Call 4455 from your Tesco Mobile number or 0345 301 4455 from any other number.
- Store: Find your nearest Tesco Mobile store and inform the assistant that you want to leave.
Note: You can request a PAC code from Tesco Mobile before getting your new SIM card, as the code is valid for 30 days.
If you want a new number and do not wish to keep your current number, you will need to request an STAC code instead of a PAC code. Text "STAC" to 75075 to get your STAC code.
2. Order a SIM only deal from Three
If you haven't yet ordered your new Three SIM Only deal, you can use our free comparison engine, which will show you the cheapest Three deals available on the market.
If you already have your new SIM Card, feel free to skip to step 3 of this article
During the ordering process you may be given the opportunity to share your PAC code from Tesco Mobile to Three, if you choose this option then the number transfer process will start once your new sim card arrives and you activate it in by putting it in your phone and turning it on, this also means you can skip to step 4 of this article if you wish!
If you are not given the opportunity to hand over your PAC code when ordering then there's no need to panic. Once your new sim card from Three has arrived, just continue to step 3 of this article.
It is also worth calling out that it doesn't matter if you are able to hand over your PAC code from Tesco Mobile whilst buying your new sim from Three or not it's just slightly more convenient but the outcome is the same!
3. Give the PAC code to Three
Giving Three your PAC code is super simple:
- Online: Just complete a quick form on the Three website and enter your PAC code. Done!
- Over the phone: Call Three on 333 from your Three SIM or 0333 338 1001 from any other phone.
- Their customer service line is open;
- Monday through Friday, 8 am to 8 pm
- Saturday and Sunday, 9 am to 6 pm.
- Their customer service line is open;
- In-store: Pop into your nearest Three-store location, and a friendly advisor will help you switch your number.
Relax and wait: Within 1-2 working days, your phone number will be transferred to Three. Easy peasy!
Remember: Your PAC code is valid for 30 days, so give it to Three within that time.
4. Wait for your number transfer to Three to complete
That's it you've done the hard work, now sit back and relax. Three will notify Tesco Mobile of your intention to leave and take your mobile number to Three.
The number transfer process will usually take 1 to 2 working days. After this time your Tesco Mobile mobile number will be working on the Three SIM card.
