Three PAC Code: keep your number and switch networks

Last Updated: 29th July 2025

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Are you thinking about leaving your current network and switching to Three? Or perhaps you are already with Three and looking to switch to a new network.

If either of the above is true 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 from your current network in order to get a new number and will cancel your existing contract.

- Joining Three from another network and keeping your number

- Leaving Three: transfer and switch your Three number to a different network

Joining Three from another network and keeping your number

Joining Three and transferring your number from your current network 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 your current network 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 your current network

Switching from your current working and joining Three is easy. There is no need to commit a new number to memory or update all your contacts!

Requesting a PAC (Porting Authorisation Code) from your current network is easy here is how:

• Text: From your current phone, text "PAC" to 65075. You will receive a text back with your code within 60 seconds. This is a free service from Ofcom (the UK's communications regulator).
• Online: Some networks will allow you to log in to your current online account and request your PAC code.
• Phone: Call your current provider's customer service phone number from your current phone.

Your PAC code is valid for 30 days, so you can request it before you get your new SIM card.

If you would like a new mobile number and don't need to keep your current number, then request a STAC code by texting "STAC" to 75075 from your current phone. This is a universal number set up by Ofcom.

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.

Compare Three SIM Only Deals

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 your current network 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 then 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 your current network 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.
• 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 your current network of your intention to leave and take your mobile number to your Three.

The number transfer process will usually take 1 to 2 working days. After this time your current mobile number will be working on your new Three SIM card.

Leaving Three: transfer and switch your Three number to a different network

Joining a new network and transferring your number from Three 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 Three and handing it to your new network.

You can either hand the PAC code over to your new network during the ordering process or after you have received your new SIM card or eSIM has been activated.

1. Request a PAC Code from Three

You can keep your current phone number, avoiding the hassle of memorising a new one or updating your contacts. You will need a PAC (Porting Authorisation Code) from Three to begin the switch.

Here is how to get it:

• Text: The quickest way is to text "PAC" to 65075 from your Three phone. You will receive your code within 2 minutes. Ofcom, the UK's communications regulator, provides this free service.
• Online: Visit Three's website and request a PAC code through their live chat service.
• 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.
• In-store: Visit a Three store and request a PAC code from a sales assistant.

Your PAC code is valid for 30 days, so you can request it before or after getting your new SIM card.

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

If you haven't yet ordered your new SIM Only deal, you can use our free comparison engine, which will show you the cheapest deals available on the market.

Compare SIM Only Deals

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 your Three to your network, 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 your new network 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 Three whilst buying your new sim from your new network or not it's just slightly more convenient but the outcome is the same!

3. Give the PAC code to your new network

Once you have your PAC code, here is how to give it to your network:

• Online: When you order your new SIM card online, you can enter your PAC code.
• Phone: Call your new network's customer service number and provide them with your PAC code.
• In-store: If your new network has a store you can visit a store, and a staff member will help you transfer your number using your PAC code.

Your new network will then handle the transfer. Your number will usually be transferred to them within 1-2 working days. Important Notes:

Remember to give your PAC code to Vodafone within 30 days.

If you would like a new Vodafone number and don't need to keep your current number, remember to get a STAC code rather than a PAC code from your current network.

4. Wait for your number transfer to your network to complete

That's it you've done the hard work, now sit back and relax. Your new network will notify Three your intention to leave and take your mobile number to your new network.

The number transfer process will usually take 1 to 2 working days. After this time your Three mobile number will be working on your new SIM card.