How to Switch to eSIM and Keep Your Number

If you're thinking about switching to eSIM, there's a good chance one question is holding you back: will you lose the number everyone already has for you? The honest answer is no — and the process is simpler than most people expect.

Your number and your SIM are separate things

This is the bit that trips people up: your mobile number doesn't live inside your physical SIM card or your network's app — it's registered to you, and any UK network can move it. Switching to eSIM is really two separate steps that happen to line up: getting a new (digital) SIM, and telling your old network to hand your number over to the new one. Neither depends on the other.

How the number part actually works

1. Get your PAC code. Text PAC to 65075 from the phone you want to keep the number on — it's free, and works with any UK network. You'll get a reply within seconds with your code, plus its expiry date (PAC codes are valid for 30 days).
2. Enter it when you activate your eSIM. At my.helloiq.uk, the activation flow asks if you want to keep your existing number — say yes and enter your PAC code there.
3. It transfers the next working day. You'll get a text confirming the switch. There's usually a brief window of a few minutes where things may be temporarily unavailable during the handover — that's normal.

Porting your number is a separate process from cancelling your old contract — worth checking your old provider's own terms if you're still within a minimum term, rather than assuming one automatically sorts out the other.

We've written the exact step-by-step for doing this with IQ Mobile — Porting Your Number to IQ Mobile →.

What actually changes with an eSIM

An eSIM is a SIM profile installed digitally rather than a physical card you fit into your phone. Practically, for most people:

• No card to wait for or lose — your eSIM QR code lands in your confirmation email, usually within a few hours of ordering
• Your phone needs to support it — most phones from the last few years do; check before ordering if you're not sure
• Setup takes a few minutes, scanning a QR code on a separate device (you can't scan it on the same phone you're activating)

Full walkthroughs for getting the eSIM itself installed: Activating eSIMs on Apple devices → and Activating an eSIM on Android →.

Putting it together

If you already know which plan you want:

1. Order your eSIM →.
2. Watch for your QR code by email, then install it following the device guide above.
3. Activate at my.helloiq.uk and choose to keep your existing number when asked — this is where your PAC code goes.
4. Your number transfers the next working day, with a text to confirm.

No new number to give out, and no long gap in service.

Frequently asked questions

Will I lose my number if I switch to eSIM? No — your number and your SIM type are unrelated. Get a PAC code by texting PAC to 65075, give it to your new network, and your number transfers within a working day.

How do I get a PAC code? Text PAC to 65075 from the phone you want to keep the number on. It's free and works with any UK network — you'll get a reply within minutes.

Does switching cancel my old contract automatically? No — porting your number is a separate process from cancelling your old contract. If you're still within a minimum term, it's worth checking your old provider's own terms rather than assuming the port handles that for you.

How long does the switch take? Usually the next working day. There's a brief window — typically a few minutes — where things may be temporarily unavailable during the handover.

Where do I actually enter my PAC code? At activation, not checkout — visit my.helloiq.uk, and the activation flow will ask if you want to keep your existing number and prompt you for the code there.

Do I need a special phone for eSIM? Most phones from the last few years support eSIM. Check your device before ordering — our activation guides cover the most common models.