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Switching·8 min read·

Switch from Three to eSIM

By Fuse Team

Why Switch from Three to Multi-Network eSIM?

Three's network has improved significantly over recent years, but you're still limited to a single network's coverage. When you switch from Three to eSIM with multi-network capability, your phone automatically connects to whichever network has the strongest signal at your location—whether that's EE, Vodafone, O2, or Three itself.

This means better coverage in rural areas, improved signal in buildings, and more reliable data speeds wherever you travel across the UK. Plus, you can keep your existing Three number throughout the switch.

Understanding the PAC Code Process

To keep your Three number when switching to eSIM, you'll need a PAC (Porting Authorisation Code) from Three. This 9-character code authorises your new provider to transfer your number.

Getting Your PAC Code from Three

Method 1: Text Message (Fastest)

  1. Text PAC to 65075 from your Three phone
  2. You'll receive your PAC code within minutes
  3. The code is valid for 30 days from issue

Method 2: My3 App

  1. Open the My3 app on your phone
  2. Tap Account at the bottom
  3. Select Leaving Three
  4. Choose Get your PAC code
  5. Follow the prompts to receive your code

Method 3: Call Three

  1. Call 333 from your Three phone (or 0333 338 1001 from any phone)
  2. Say "PAC code" when prompted
  3. You may be transferred to the disconnections team
  4. They'll provide your PAC code and may offer retention deals

Important: Three cannot charge you for providing a PAC code, and they must provide it within two hours of your request during business hours.

Choosing Your Multi-Network eSIM Plan

Before requesting your PAC code, decide which plan suits your usage. Multi-network eSIMs typically offer better value than Three's equivalent plans because you're getting access to all four UK networks.

Comparing Three Plans vs Multi-Network Options

Three's Current Pricing (as of 2024):

  • Advanced: £10/month (12GB)
  • Essential: £16/month (100GB)
  • Ultimate: £20/month (Unlimited)

Multi-Network eSIM Benefits:

  • Automatic network switching for best coverage
  • Better building penetration
  • Improved rural coverage
  • Often better value for equivalent data allowances
  • No contract tie-ins with most providers

Our plans start from £8/month with 5GB on all four networks, scaling up to unlimited data options that often cost less than Three's equivalent single-network plans.

Step-by-Step Switching Process

Step 1: Order Your Multi-Network eSIM

  1. Choose your preferred multi-network eSIM provider
  2. Select a plan that matches or exceeds your current Three allowance
  3. Complete the order process online
  4. You'll receive a QR code via email for eSIM activation

Step 2: Install the eSIM (Don't Activate Yet)

For iPhone:

  1. Go to Settings > Mobile Data
  2. Tap Add eSIM
  3. Select Use QR Code
  4. Scan the QR code from your email
  5. Follow the setup prompts but don't activate the plan yet
  6. Label it something like "New eSIM" to distinguish it

For Android:

  1. Open Settings > Network & Internet
  2. Tap Mobile Network > Add Carrier
  3. Select Use QR Code or Enter Code Manually
  4. Scan your QR code
  5. Complete setup but keep your Three SIM as the active line

Step 3: Request Number Transfer

Once your eSIM is installed but not activated:

  1. Contact your new eSIM provider's customer service
  2. Provide your PAC code from Three
  3. Confirm the number you want to transfer
  4. Choose your preferred transfer date (usually 1-2 working days)

The transfer typically happens between 9 AM and 5 PM on your chosen date.

Step 4: Transfer Day Process

Morning of Transfer:

  • Keep your Three SIM active until the transfer completes
  • Ensure your phone is charged and has good signal
  • Stay near WiFi if possible

During Transfer (Usually Takes 2-4 Hours):

  1. Your Three service will stop working
  2. You may lose signal briefly
  3. Your new eSIM will automatically activate with your transferred number
  4. Test calling, texting, and data to confirm everything works

After Transfer:

Four UK networks, one eSIM. No contract.

Get connected to all four UK networks and never worry about signal again.

Try free for 7 days
  • Remove your physical Three SIM card
  • Update your phone's mobile data preferences if needed
  • Your Three account will automatically close

Network Coverage Comparison

Three's Network Limitations

Three operates on higher frequency bands (mainly 1800MHz and 2100MHz) which provide good speeds but struggle with:

  • Building penetration
  • Rural coverage
  • Underground areas
  • Dense urban environments

Multi-Network Advantages

With multi-network eSIM, you get access to:

EE's Network:

  • Best overall UK coverage (99% population)
  • Strong rural presence
  • Excellent 4G and 5G speeds

Vodafone's Network:

  • Good urban coverage
  • Strong international roaming
  • Reliable voice quality

O2's Network:

  • Excellent building penetration
  • Strong in major cities
  • Good customer satisfaction ratings

Three's Network:

  • Competitive speeds in covered areas
  • Good value data allowances
  • Strong 5G rollout in cities

Your phone automatically selects whichever network provides the strongest signal, giving you the best of all four networks. Learn more about how multi-network coverage works.

Timeline and What to Expect

Before Transfer Day

  • Day -3 to -1: Order eSIM, install but don't activate
  • Day -2 to -1: Request PAC code from Three
  • Day -1: Confirm transfer details with new provider

Transfer Day

  • 9:00 AM: Transfer window opens
  • Usually 10:00 AM - 2:00 PM: Transfer completes
  • 5:00 PM: Transfer window closes

After Transfer

  • Immediately: Test all services (calls, texts, data)
  • 24-48 hours: Monitor for any issues
  • 7 days: Three account automatically closes

Troubleshooting Common Issues

eSIM Won't Activate After Transfer

  1. Restart your phone
  2. Check you're in an area with good signal
  3. Try toggling aeroplane mode on and off
  4. Contact your new provider's support team

Calls Working But No Data

  1. Go to Settings > Mobile Data
  2. Ensure your new eSIM is selected for mobile data
  3. Check APN settings are correct
  4. Reset network settings if problems persist

Can't Receive Texts

  1. Verify the transfer completed successfully
  2. Check your message centre number
  3. Try sending a text to yourself
  4. Contact customer support if issues continue

Benefits You'll Notice After Switching

Immediate Improvements

Better Coverage: Access to four networks means signal in previously dead zones

Faster Speeds: Your phone connects to the least congested network automatically

Building Penetration: Different networks use different frequencies, improving indoor signal

Long-Term Advantages

No Contracts: Most multi-network eSIM providers offer monthly rolling contracts

Better Value: Often more data for less money than single-network plans

Future-Proof: As networks improve, you benefit from all upgrades automatically

Travel Benefits: Better coverage across the UK for business or leisure travel

Cost Comparison and Savings

Switching from Three to multi-network eSIM often results in immediate savings:

Monthly Cost Comparison

Three Essential (100GB): £16/month Multi-Network 100GB: Typically £12-14/month Annual Saving: £24-48

Three Ultimate (Unlimited): £20/month Multi-Network Unlimited: Typically £15-18/month Annual Saving: £24-60

Additional Value

  • No early termination fees with monthly contracts
  • Better coverage means less frustration
  • Often better customer service
  • Access to latest network technologies across all providers

Check current coverage maps to see how multi-network eSIM could improve your specific locations.

What Happens to Your Three Account

Once your number transfers successfully:

  1. Automatic Closure: Your Three account closes automatically within 7 days
  2. Final Bill: You'll receive a final bill for any remaining charges
  3. Direct Debit: Cancel any Direct Debit mandates to avoid confusion
  4. Device Plans: If you have a device plan, this continues separately
  5. Add-ons: All Three add-ons and bolt-ons are cancelled

Frequently Asked Questions

How long does it take to switch from Three to eSIM?

The actual number transfer takes 2-4 hours on your chosen transfer day. However, the entire process from ordering your eSIM to completing the switch typically takes 2-3 days. You can install the eSIM immediately but should wait until you have your PAC code before requesting the number transfer.

Will I lose my WhatsApp messages when switching?

No, WhatsApp messages are tied to your phone number, not your network. Once your number transfers to the new eSIM, WhatsApp will continue working normally with all your chat history intact. The same applies to other apps that use your phone number for verification.

Can I keep my Three email address after switching?

Three doesn't provide email addresses, so this isn't a concern. If you're thinking of a different service, most email providers (Gmail, Outlook, etc.) are independent of your mobile network and will continue working normally after switching.

What if I change my mind during the switching process?

Before providing your PAC code, you can cancel without penalty. Once you've given your PAC code to your new provider and confirmed the transfer date, the process becomes difficult to reverse. However, you could potentially get a new PAC code from your new provider to switch back to Three, though this would involve additional costs and time.

Do I need to unlock my phone to switch to eSIM?

If your phone is locked to Three, you'll need to unlock it before using a different network's eSIM. Three typically unlocks phones free of charge for existing customers. Contact Three customer service to request an unlock code before starting your switch.

Switching from Three to a multi-network eSIM gives you better coverage, often better value, and the flexibility of accessing all four UK networks automatically. The process is straightforward, and you'll keep your existing number throughout the switch, making the transition seamless for your contacts.

Ready to try multi-network data?

Get connected to all four UK networks in minutes.