The most important distinction when buying a virtual number is non-VoIP versus VoIP. It matters more than price or country: with the wrong line type, the verification code never arrives at all.
Short answer
A non-VoIP number is registered on a real mobile carrier network and corresponds to a physical SIM. It receives SMS like an ordinary mobile phone.
A VoIP number is generated over the internet and is not tied to a carrier network. Numbers from services like Google Voice or TextNow fall into this group.
Why does the difference matter?
Large platforms classify number ranges to stop fake account creation. VoIP ranges can be generated free and without limit, so they are treated as automation-friendly and filtered out.
| Property | Non-VoIP | VoIP |
|---|---|---|
| Infrastructure | Real carrier network | Over the internet |
| WhatsApp acceptance | High | Very low |
| OpenAI / ChatGPT | High | Usually rejected |
| High | Low | |
| Telegram | High | Medium |
| Banking / official services | Limited | Rejected |
| Cost | Higher | Very low / free |
In short: VoIP is cheap because it does not work. The price of a number that never receives the code is irrelevant.
How do I tell which type it is?
You cannot judge by the prefix alone; the same country code contains both VoIP and non-VoIP ranges. Practical checks:
- Read the provider's description. Serious providers state the line type openly.
- Run a test verification. If a strict service like WhatsApp accepts it, the line is very likely non-VoIP.
- Watch the price. A real carrier line has a cost; unlimited numbers priced near zero are usually VoIP.
The lines offered on SimBlink come from real carrier networks, which is why they work on picky services like WhatsApp and OpenAI. You can check current availability per service and country on the buy a number screen.
The "VoIP numbers are not accepted" error
If you see this message, check in order:
- Confirm the line is non-VoIP.
- Match the number's country to the country of the IP you are connecting from.
- Try a second number from the same country — it will have a different history.
Every order where no code arrives is refunded automatically, so retrying costs nothing. The rules are on the refund policy page.
Frequently asked questions
Is a non-VoIP number more expensive? Yes, because there is a real carrier cost behind it. But money spent on a cheap number that gets rejected is entirely wasted, so non-VoIP is cheaper in total.
Does every country have non-VoIP lines? No, stock varies by country and service. You can see the country list and live availability on the order screen.
Do I keep the non-VoIP number permanently? No. It is for a single verification; once finished the number returns to the pool. For a permanent line you need a contract with a carrier.
Is it the same as an eSIM? No. An eSIM is the digital form of a physical SIM and is assigned to you permanently. A number here is issued temporarily for one verification.
Keep reading
Service guides: Instagram virtual number, ChatGPT / OpenAI, WhatsApp. For the fundamentals read what is SMS verification. We cover the account-safety side in will a virtual number account get banned. Questions? Support is here.
