Second phone number vs a second SIM: which is better?
A second number in an app gives you an extra UK line without a second SIM, a spare SIM slot or another plan - it lives in the app on the phone you already own. A second SIM means a new physical or eSIM from a network, a slot to put it in, and its own tariff. For most people who just want a separate line for privacy, work or selling, the app is simpler and cheaper.
What's the difference?
Both give you a second phone number, but they get there very differently:
- A second SIM is a real SIM (or eSIM) from a mobile network. You need a phone with a spare SIM slot or eSIM support, you activate it with a network, and it comes with its own plan and bill.
- An app-based second number (like nothanumber) runs over the internet - Wi-Fi or mobile data - through an app on your existing phone. There's nothing physical to insert and no second handset. You add a UK number in minutes and use it alongside your normal one.
Do you need a dual-SIM phone?
For a second SIM, yes - you need a phone with two SIM slots or eSIM support, or you end up swapping SIMs. For an app-based number, no: it's just an app, so any modern phone works and both lines live side by side.
Which is cheaper?
For light, everyday use, the app usually wins. nothanumber charges a small monthly rental to hold a number (from around £4.99 a month) with calls and texts pay-as-you-go from one wallet, and no separate contract. A second SIM typically means another tariff to pay for and manage. If you need a lot of independent mobile data, a second SIM can work out better - which brings us to when a SIM wins.
Which keeps your number more private?
Both keep your personal number off the table, because you hand out the second one. With an app-based number the calls and texts you send show that number, not your real mobile, and everything sits in one app you control - handy for selling online, dating or a work line you can quiet out of hours.
When is a second SIM the better choice?
Being honest: a second SIM is the better option when you need cellular service that works without internet - a dependable line where there's no Wi-Fi or mobile data - or when you specifically want a separate mobile data allowance. An app-based number needs a working internet connection, because it runs over the internet. For most privacy, work and selling use-cases that isn't an issue, but it's the honest dividing line.
At a glance
- Extra hardware - second SIM: a SIM and a spare slot (or a swap). App number: none.
- Setup - second SIM: activate with a network. App number: add a number in the app in minutes.
- Cost - second SIM: its own plan. App number: small monthly rental + pay-as-you-go.
- Needs internet - second SIM: no. App number: yes.
- Best for - second SIM: independent cellular/data. App number: a private, separate line with no fuss.
Common questions
Can I get a second number without a second SIM?
Yes. An app-based second number, like nothanumber, runs over the internet on the phone you already own - there's no second SIM to buy, no spare SIM slot needed and no second handset.
Is an app-based second number cheaper than a second SIM?
Usually, for light use. nothanumber charges a small monthly rental (from around £4.99 a month) plus pay-as-you-go calls and texts, with no separate contract. A second SIM often means another plan to manage. If you need a lot of independent mobile data, a second SIM can still make sense.
When is a second SIM the better choice?
When you need cellular service that works without internet - for example a reliable line in areas with no Wi-Fi or mobile data, or a separate mobile data allowance. An app-based number needs a working internet connection because it runs over the internet.
nothanumber gives you an app-based second UK number - mobile or landline - with calls, texts and voicemail built in. It's ready, and access is invite-only for now - join the waitlist for your spot.