The right second phone number depends on what it is for. For calls and texts you keep for months, an eSIM or a second SIM in a dual-SIM phone is the sturdiest choice. A calling app is quicker but often refused by sign-up forms. If you only need a code to sign up somewhere without giving your own number, a one-time number does that and nothing more.
What do you need the second number for?
- Calls
- You need a line that rings and that people can call back. Rules out receive-only numbers.
- Chats in WhatsApp or Telegram
- The messenger ties the account to the number and may ask for it again on a new phone. Needs a number that lasts.
- Sign-up codes
- One text, once. The number only has to work for a few minutes.
Five options compared
| Calls and sending texts | How long | Accepted for codes | |
|---|---|---|---|
| Second physical SIM | Yes | As long as the plan runs | Yes, a normal mobile number |
| eSIM | Yes | As long as the plan runs | Yes, a normal mobile number |
| Calling or second-line app | Yes, over the internet | While you subscribe | Often refused as VoIP |
| Cheap second phone with prepaid SIM | Yes | Until the credit lapses | Yes |
| One-time number | No, receives texts only | Up to ten minutes | Built for this, success varies by app |
Prepaid lines can be switched off after a long time without top-ups. Check your carrier's rules before relying on one.
Adding a second line on iPhone and Android
- iPhone: Apple's Dual SIM lets you keep two numbers active for calls and texts. iPhone 13 and later can hold two eSIMs; older dual-SIM models pair a nano-SIM with an eSIM.
- Labels: name each line, such as Personal and Business, and choose which one iMessage and FaceTime use.
- Pixel: from Pixel 3a on you can use one physical SIM plus one eSIM; Pixel 7 and later can run two eSIMs if the carrier supports it.
- Defaults on Android: Settings → Network & internet → SIMs, then pick the SIM for calls and texts, or Ask every time.
- Data: both platforms use one line for mobile data at a time.
When a one-time number is enough
- A shop, a marketplace or a newsletter wants a number at sign-up and you do not want marketing texts.
- You are testing an app and do not want your own number tied to it.
- An app asks once and does not check again; services such as TikTok, Discord or Reddit usually work this way.
It is the wrong choice for a WhatsApp account you will use for years, or a second WhatsApp account on the same phone: those can ask for the number again.
What to compare before you pay
- Does it receive codes from the apps you use? Internet-calling numbers are the most common reason for a refused sign-up.
- What happens if you stop paying? A lapsed number goes back to the provider and may later belong to someone else, along with any account that still uses it.
- Can you move the number? SIM and eSIM numbers can usually be moved to another carrier. App numbers often cannot.
- Do you need calls at all? If not, you may not need a second line, only a code.
Common questions
Can I get a free second phone number?
Some calling apps offer one, but sign-up forms often refuse those numbers. A second SIM or eSIM costs a plan but is accepted almost everywhere.
Can one phone have two numbers?
Yes, if it supports dual SIM: two physical SIMs, a SIM plus an eSIM, or two eSIMs on newer models.
Is a one-time number a second phone number?
Only for a few minutes. It receives one code and cannot call or send texts, so it is not a second line.
Which second number is best for WhatsApp?
One you keep, such as an eSIM or a second SIM. WhatsApp can ask for the number again when you change phones.