How to Change Your Mobile Network from One SIM to Another in the UK

Switching your mobile network in the UK has become easier than ever. Thanks to regulations and advancements in mobile services, you can change your mobile service provider without needing to switch your phone number or experience a lengthy transition process. This guide will cover everything you need to know about changing your mobile network from one SIM to another, focusing on UK mobile networks, options, processes, and troubleshooting.

Table of Contents

1. Why Switch Mobile Networks?

   • Coverage and Service
   • Pricing and Plans
   • Network Speed and Performance
   • Customer Support and Service
   • Roaming and International Services

2. UK Mobile Networks Overview

   • Major Networks: Vodafone, EE, O2, and Three
   • MVNOs (Mobile Virtual Network Operators)

3. Preparation Before Switching

   • Check Network Coverage
   • Unlock Your Phone
   • Check Contract Termination Fees
   • Backup Your Contacts and Data

4. Methods of Switching

   • Using a PAC Code
   • Using a STAC Code
   • Switching Through a New SIM-Only Deal
   • eSIM Option

5. Steps to Switch Your Network

   • Acquiring Your PAC or STAC Code
   • Selecting a New Network Provider
   • Activating Your New SIM
   • Testing the Transition

6. Network-Specific Instructions

   • Vodafone SIM Swap
   • EE SIM Swap
   • O2 SIM Swap
   • Three SIM Swap

7. Common Challenges and Troubleshooting

   • SIM Not Working
   • Network Coverage Problems
   • Number Porting Delays

8. Roaming, International Considerations, and 5G

   • Understanding Roaming Policies
   • Switching Networks for Better Roaming Deals
   • 5G Compatibility and Speeds

9. Conclusion

1. Why Switch Mobile Networks?

Switching your mobile network can offer numerous benefits, especially if your current service provider no longer meets your needs. Here are some common reasons people in the UK switch mobile networks:

Coverage and Service

Mobile coverage is one of the main reasons people change networks. Some networks have better coverage in certain areas. For example, EE is known for having broad coverage across the UK, but if you live in a rural area or travel frequently, Vodafone or O2 might have better service in your specific location.

Pricing and Plans

Pricing is a major factor in deciding which mobile network to use. UK providers often have various pricing plans, such as pay-as-you-go (PAYG), SIM-only deals, and contract plans. If your current network is too expensive or lacks flexibility, you might find a more affordable or tailored plan elsewhere.

Network Speed and Performance

The UK mobile market has seen significant improvements in terms of speed and performance. If your current network is not providing fast 4G or 5G speeds, switching to a provider that offers better coverage and speed could enhance your overall experience.

Customer Support and Service

Customer support varies significantly across networks. If you are not satisfied with the level of support, ease of reaching customer service, or the resolution of issues, it may be worth switching to a network known for superior customer service.

Roaming and International Services

If you travel abroad often, roaming services become a vital aspect of your mobile plan. While EU roaming was previously included for free under EU regulations, Brexit has caused changes, and different networks now offer varying roaming deals. Switching to a network with better roaming options can save you a lot of money when abroad.

2. UK Mobile Networks Overview

Major Networks

In the UK, four major mobile networks dominate the market:

1. Vodafone: Known for strong international roaming plans and solid nationwide coverage.
2. EE: Part of BT, EE boasts one of the fastest 4G and 5G networks and excellent coverage across the UK.
3. O2: Famous for flexible pricing plans, good coverage, and customer perks like Priority.
4. Three: Typically offers competitive pricing and unlimited data options.

These networks operate their own infrastructure and are known for comprehensive mobile coverage in most urban and rural areas across the UK.

MVNOs (Mobile Virtual Network Operators)

In addition to these main players, MVNOs (Mobile Virtual Network Operators) operate by renting network space from major providers. MVNOs often offer more affordable packages by leveraging existing infrastructure. Some of the most popular MVNOs in the UK include:

• Giffgaff (operating on O2’s network)
• Tesco Mobile (O2)
• Sky Mobile (O2)
• BT Mobile (EE)
• Virgin Mobile (EE)
• ASDA Mobile (Vodafone)

3. Preparation Before Switching

Check Network Coverage

Before switching, ensure your new network has good coverage in your area. Coverage can vary between networks, especially in rural or remote areas. Most UK networks provide coverage checkers on their websites, allowing you to see how well their signal reaches your home or workplace.

Unlock Your Phone

If you bought your phone directly from a mobile network, it may be locked to that network. Before switching to a new network, you need to unlock your phone. Fortunately, UK networks are required by law to unlock phones free of charge, but the process can take a few days.

You can contact your current provider or use an online service to check if your phone is locked. If it is, your provider should give you instructions on unlocking it, which may involve using an unlocking code.

Check Contract Termination Fees

If you're still under contract with your current provider, switching networks might result in early termination fees. Check the details of your contract to see if there are any penalties for leaving before the end of the term. Some networks may allow you to switch early without hefty fees if you're moving to a new contract with them or a partner network.

Backup Your Contacts and Data

Ensure you back up all your contacts, messages, and essential data before switching networks. If you're switching to a new SIM card, you don't want to lose your contacts or other information stored on your old SIM. Most smartphones offer cloud backup services or options to store data on the device.

4. Methods of Switching

Using a PAC Code

A PAC (Porting Authorisation Code) is a nine-character code that allows you to keep your current phone number when switching networks. It’s the easiest and most popular method of switching networks in the UK.

Steps to switch with a PAC code:

1. Text PAC to 65075 to receive your PAC code from your current provider.
2. Provide the PAC code to your new network, either during sign-up or via their customer service.
3. Your number should be transferred to the new network within one working day.

Using a STAC Code

If you don’t want to keep your old number, you can use a STAC (Service Termination Authorisation Code) instead. This will terminate your old contract without porting the number to your new SIM.

Steps to switch with a STAC code:

1. Text STAC to 75075 to receive your STAC code.
2. Provide the STAC code to your new network.
3. The switch should happen within one working day, and you’ll be assigned a new number.

Switching Through a New SIM-Only Deal

If you’re switching to a SIM-only deal without needing to transfer a number or terminate an existing contract, the process is much simpler. You can purchase a SIM-only plan from the new provider, insert the new SIM, and activate it by following the provider’s instructions.

eSIM Option

Many newer smartphones now support eSIM, which eliminates the need for a physical SIM card. To switch networks with an eSIM, you’ll need to check whether your new provider supports eSIM. Activation is generally straightforward and involves scanning a QR code provided by your new network.

5. Steps to Switch Your Network

Acquiring Your PAC or STAC Code

To switch networks while keeping your number (PAC) or getting a new number (STAC), follow the text commands above to obtain the relevant code from your current provider.

• Text PAC to 65075 if you want to keep your number.
• Text STAC to 75075 if you want a new number.

This service is free, and you should receive the code immediately. Once you receive the code, it remains valid for 30 days.

Selecting a New Network Provider

Once you have your PAC or STAC code, shop around for the best deals. Many UK providers offer attractive SIM-only deals or phone bundles. Consider the coverage, pricing, data allowances, and roaming options before making your decision.

Activating Your New SIM

After selecting your new provider and receiving your new SIM card, you’ll need to activate it. Activation processes vary slightly between networks but generally involve inserting the SIM into your phone and following on-screen instructions or a web-based setup.

Testing the Transition

Once your number has been transferred or your new number activated, test your phone to ensure the switch was successful. Make calls, send messages, and use mobile data to confirm everything is working smoothly.

6. Network-Specific Instructions

Vodafone SIM Swap

To switch to Vodafone or change your SIM:

1. Obtain a PAC or STAC code from your old provider.
2. Register for a Vodafone SIM or SIM-only plan.
3. Provide Vodafone with your PAC or STAC code during the sign-up process.
4. Insert your new Vodafone SIM and wait for activation.

EE SIM Swap

If you’re switching to EE:

1. Get your PAC or STAC code from your previous provider.
2. Sign up for an EE SIM or phone contract.
3. Enter your PAC or STAC code during the sign-up process or by contacting EE’s customer service.
4. Activate your new SIM and ensure the number porting is completed within 24 hours.

O2 SIM Swap

For O2 customers:

1. Secure your PAC or STAC code from your old network.
2. Choose your O2 plan and provide the PAC or STAC during the registration.
3. Insert your O2 SIM and confirm the switch has occurred by testing your network.

Three SIM Swap

To switch to Three:

1. Request a PAC or STAC code from your current network.
2. Choose a Three SIM plan.
3. During registration, provide your PAC or STAC code to start the transfer.
4. Once activated, test your new SIM for full functionality.

7. Common Challenges and Troubleshooting

SIM Not Working

If your new SIM isn’t working after inserting it, ensure you’ve activated it by following your network’s setup instructions. You may need to restart your phone or contact customer support if problems persist.

Network Coverage Problems

After switching, if you experience poor network coverage, use your new provider’s coverage checker to see if your area is fully supported. If you live in a weak coverage area, consider switching back or using Wi-Fi calling if your provider supports it.

Number Porting Delays

Number porting can take up to 24 hours but usually happens much faster. If your number hasn’t transferred within that period, contact your new provider’s customer service for assistance.

8. Roaming, International Considerations, and 5G

Understanding Roaming Policies

Roaming charges have changed for UK residents traveling to the EU since Brexit. Some networks now charge for EU roaming, while others offer inclusive plans. If you travel frequently, consider this when choosing a network.

Switching Networks for Better Roaming Deals

If your current network has expensive roaming charges, it may be worth switching to a provider with better deals for international travel. For example, Vodafone and Three often offer more competitive rates for roaming outside the UK.

5G Compatibility and Speeds

If your phone supports 5G, you may want to switch to a network with good 5G coverage. EE and Vodafone are currently leaders in 5G availability across the UK, but coverage can vary depending on location.

9. Conclusion

Switching mobile networks in the UK is a simple process, made even easier by regulations like the PAC and STAC system. By following the steps outlined in this guide, you can seamlessly transition between providers, ensuring you benefit from better pricing, coverage, and service.