A US number is only useful if people can reach you. So what happens when someone calls while you are on a flight, your battery is dead or your data drops? With an app-based number, the answer is voicemail. Here is how it works and how to set it up so you do not miss anything.
How is an app number different from a SIM?
A carrier number rings over the mobile network. A virtual number rings an app over the internet. That is what lets you answer a US call from hotel Wi-Fi or local mobile data anywhere in the world. It also means your internet, your notification settings and your phone’s background rules all affect whether the phone rings.
With the TripoSIM US Virtual Number, calls reach the app while you are online. If your phone is off, offline or has notifications blocked, the caller goes to voicemail. It is not a replacement for your local line in an emergency.
For the full picture of how calls reach the app, see how the TripoSIM number works.
What are the voicemail limits?
| Limit | TripoSIM number |
|---|---|
| Longest message | 2 minutes |
| Messages per month | up to 30 |
| How long messages are kept | 30 days |
| Incoming call allowance | 300 minutes a month, fair use |
When you go over the incoming allowance, callers go straight to voicemail until the next month.
What that means in practice: if you expect dozens of callers a day, 30 messages a month will not be enough. If you want clients, family or a landlord to reach you while you travel, it usually is.
How do you set up your phone so calls ring?
- Set up the app. On iPhone, add the TripoSIM web app to your Home Screen. On Android, install the TripoSIM app.
- Allow notifications and microphone access. Without them the app may not ring, or the caller may not hear you. TripoSIM says calls ring even when the app is closed once notifications and the microphone are allowed; a phone that is off, offline or has notifications blocked does not ring, and callers reach voicemail.
- Test on both your usual mobile data and Wi-Fi before you share the number.
- Ask someone to call you three times: with the app open, with it in the background, and with your internet switched off. The last call should go to voicemail.
- Find the voicemail section and play back the test message before you travel.
Our calling abroad page has more on calling the US and Canada from the app.
What should you tell callers?
Write the number in international format: +1, the area code, then the seven-digit number. You do not have to explain virtual numbers to anyone. Do be honest about when you answer.
A sample email signature:
US line: +1 (your area code) XXX-XXXX. I answer calls 9am to 5pm US Eastern. Outside those hours, leave a voicemail and I will call back.
Use your own assigned number, never a sample number.
If people might text you, add a line saying the number receives texts but you cannot reply by text. The TripoSIM number can receive texts from US and Canadian senders, but not send them.
What if a call does not ring?
Check in this order:
- Is your plan active?
- Is your internet working? Try switching between Wi-Fi and mobile data.
- Are notifications and microphone access allowed for the app?
- Is internet calling restricted where you are?
If it still does not ring, contact support with the rough time, the country the caller was in and a screenshot of your call log. Never send your password or a verification code in a support request.
The short version
Voicemail makes an app-based US number much more dependable. It does not remove the need for a good connection and the right app settings. Check that 30 messages a month and 300 incoming minutes fit your use, then set up a greeting with your hours.