Real SIM vs VoIP vs Free Numbers
The right number type depends on what the target platform checks. This page compares the three options so you can pick per use case instead of per price.
The three options
- Carrier SIM (what we rent) — real T-Mobile numbers, not VoIP;
- VoIP — internet-routed numbers;
- Free public numbers — shared inboxes everyone can read.
Comparison
| Dimension | Carrier SIM | VoIP | Free public |
|---|---|---|---|
| Type | Carrier | Internet | Mixed / abused |
| Strict platforms | High pass rate | Low | Almost never |
| Privacy | Private link | Depends | Public |
| Renewable | Yes (30 days) | Sometimes | No |
| Best for | Signup, verification, long-term | Casual sites | Nothing important |
Why VoIP fails more often
- Carrier databases identify the range instantly;
- VoIP numbers are reused far more often;
- OpenAI, Google, banks and many marketplaces refuse them outright.
Three risks of free numbers
- Anyone can read your codes;
- The number is already blacklisted by major platforms;
- Account recovery via SMS can be hijacked.
When VoIP or free numbers are acceptable
- Throwaway tests with no assets;
- Marketing SMS you do not care about;
- Testing your own SMS delivery.
When only a carrier number works
- OpenAI/ChatGPT, Claude, Google Voice;
- Banks, brokers and payment services;
- Accounts you will keep and re-verify;
- Bulk or automated verification flows.
The real cost of a cheap number
Three failed attempts at 0.02 USDT cost more in time, retries and risk-score damage than one 0.07-0.30 USDT carrier number that works. Our social tiers start around 0.07 USDT and AI tiers at 0.15-0.30 USDT.
How to tell if a platform is strict
- Money or identity involved → strict;
- Requires both e-mail and phone → strict;
- Community reports of VoIP rejection → strict;
- Test with one carrier number before scaling.
Top up with USDT or Alipay/WeChat, buy the number in the market and read the code in your private SMS link. See live prices and the number market.
Open the marketContact supportFAQ
What is the core difference?
Whether a real carrier issued the number. Carrier records exist in operator databases; VoIP ranges are identifiable.
Why not use free numbers?
Public inboxes, already blacklisted, and unsafe for anything valuable.
Are VoIP numbers ever useful?
For casual sites and non-sensitive SMS only.
Can carrier numbers be long-term?
Yes — 2-30 day tiers, renewable in 30-day blocks.
How do I know a platform is strict?
If money or identity is involved, assume strict; test with one number.
How much do carrier numbers cost?
From about 0.07 USDT for social apps, 0.15-0.30 USDT for AI services.
One number for several platforms?
Technically possible; use one number per account on strict platforms.
Do you offer free numbers?
No — we only rent US T-Mobile carrier numbers.