People want a second UK mobile number for very different reasons — and the right solution depends entirely on what you actually need it to do. A second SIM makes sense in some situations and is completely wrong in others.
This guide covers every option available in the UK, what each one is actually good for, and where each one falls short.
Why do people want a second number?
The most common reasons, broadly:
- Work/personal separation — keeping client calls off your personal phone, or having a number you can genuinely switch off in the evenings.
- Privacy — a number to give out to strangers, listings, sign-ups, and anyone you're not sure about.
- Living abroad — a UK number that stays active while you're based elsewhere.
- Keeping an old number active — you're changing your main number but don't want to lose access to the old one.
- SMS verification — receiving verification codes for a second account on a service that allows only one number per account.
These are genuinely different use cases. Here's how each option maps to them.
Option 1: A second physical SIM
Second SIM Works, with caveats
Get a PAYG or contract SIM from any UK network. Put it in a second phone, or use a dual-SIM handset to run both numbers on the same device.
Works well for
- Receiving calls on the same device
- Full two-way SMS
- WhatsApp on a separate number
Drawbacks
- Costs the same as a main contract
- Requires a physical device
- Doesn't work if you're abroad long-term
- Managing two active SIMs is faff
Best for: Work/personal separation on one device, especially if you need to make outbound calls on the second number. Not suitable if you want to receive UK texts while living abroad, or if you want a low-maintenance "public" number.
Option 2: Dual-SIM phone with an eSIM
Dual-SIM / eSIM Convenient but limited
Most modern iPhones and Android flagships support dual-SIM via a physical SIM plus an embedded eSIM. Some networks — including EE, Vodafone, and O2 — offer eSIM plans.
Works well for
- No second physical SIM card
- Easy switch between numbers
- Full call and SMS capability
Drawbacks
- Still needs the phone to be on
- eSIM plans not always cheaper
- Doesn't help if you're abroad and roaming costs apply
Best for: Work/personal split on a modern smartphone, where you want to make and receive calls on both numbers. Same limitations as a second SIM if you need a number that works independently of a handset.
Option 3: VoIP number (Skype, Google Voice, etc.)
VoIP number Limited for UK use
VoIP (Voice over IP) services assign a virtual number that routes calls and sometimes texts over the internet. Skype Numbers, for example, give you a UK number that rings in the Skype app.
Works well for
- Inbound calls routed to an app
- No SIM required
- Can work from abroad
Drawbacks
- Often not a genuine 07 mobile number
- SMS verification usually doesn't work
- Requires an app to be open
- Google Voice not available in UK
- Skype numbers often blocked by banks
Best for: Very little, in the UK. VoIP numbers are primarily a US solution. UK banks, HMRC, and most verification systems specifically reject non-mobile numbers. If you need a number that works for SMS verification or UK financial services, a VoIP number will probably let you down.
Option 4: Virtual UK mobile number
Virtual mobile number Best for most use cases
A genuine UK 07 number — on the UK mobile network — that isn't tied to a SIM card. Instead of routing to a handset, incoming texts and calls are forwarded to you via email or a dashboard. The number behaves exactly like a real mobile number to anyone contacting it.
Works well for
- SMS verification on any service
- Works from anywhere in the world
- No handset or app needed
- Bring your existing number via port
- Low maintenance, just email
Drawbacks
- Receive-only (no outbound SMS/calls)
- Not suitable if you need to call back on that number
Best for: Privacy (a number you hand out freely without exposing your real one), living abroad with UK accounts, keeping an old number active, SMS verification, and any situation where you need to receive messages but don't need to send from that number.
At a glance
How to decide
You need to make outbound calls on the second number → Second SIM or eSIM. A virtual number is receive-only.
You want to separate work and personal on one phone → Dual-SIM with an eSIM plan, or a second SIM in a cheap handset you keep at your desk.
You've moved abroad but still have UK accounts and services → Virtual mobile number. It keeps working from anywhere with no roaming, no handset, no ongoing SIM management.
You want a number to give out freely without exposing your real one → Virtual mobile number. You can keep it for years as your "public" contact, or swap it if it gets overexposed.
You're keeping an old number after switching to a new one → Port your old number to a virtual service. It stays active and receives anything sent to it — you just don't need the old SIM or contract any more.
You need SMS verification for a second account → Virtual mobile number on the UK mobile network. VoIP numbers won't work for this; a genuine 07 number will.
Porting tip: If you're changing your main number and want to keep the old one active, you can port it to Privify before cancelling your old contract. Text PAC to 65075 from your old SIM to get the code — the port takes about 24 hours and your old contract ends automatically. Read our full guide to PAC codes →
A second UK number, no SIM required
Get a genuine 07 number forwarded to your email. Works for SMS verification, works abroad, works without a handset.
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