“Free US number” is one of the most searched phrases around US numbers, and there are real free options. The catch is not the price. It is who else can see your messages, how long the number stays yours, and whether the service you are signing up for will accept it. Here is what each type actually gives you.
What are the five types?
| Type | Who can read your codes | How long the number is yours | Calls | Good for |
|---|---|---|---|---|
| Public SMS inbox website | Anyone on the internet | It was never yours | No | Nothing you want to keep |
| Free ad-supported app | You | Until it is reclaimed for inactivity | Usually | Casual use, if the service accepts it |
| Google Voice (free personal) | You | While you use it; may be reclaimed after 3 months idle | Yes, from the US | People in the US with a US phone |
| Per-code rental service | You, for one code | Minutes, for one code | No | One sign-up you will never need to recover |
| Paid app number (e.g. TripoSIM) | You | While your plan is active | Yes | Accounts, work and contacts you want to keep |
The rest of this guide explains each row.
Why are public SMS inbox sites risky?
These websites list a handful of US numbers and show every text those numbers receive on a public page. That is the whole product. Anyone who opens the page sees the same codes you do, at the same moment.
That makes them dangerous for anything real. If you receive a login code there, someone else can use it. If the account later asks you to confirm the number again, you have no way to get that code privately. The same numbers are reused by so many people that none of them is really yours.
Use them for nothing you would mind a stranger controlling. In practice, that means almost nothing.
Do free ad-supported apps work for verification?
Free calling and texting apps give you a number of your own, which is better. One limit matters most.
They can be taken back. TextNow’s support centre says “there’s no hard-and-fast rule as to how long a number can stay inactive before it’s revoked,” and that a new number can expire within 24 hours if you don’t use it to call or text. Once a number is released, you cannot get that number back. Someone else may get it, along with any codes meant for you. Our guide to number recycling and account security covers what to do before that happens.
What about Google Voice?
Google Voice is free for personal use and works well, inside its rules. Google describes its personal Voice plans as for individual users in the US, with US numbers only. Setup texts a code to a phone you already have. If you live abroad without a US number, that usually rules it out. See Google Voice alternatives outside the US.
Google also says it may reclaim a number if you don’t appear to be using it, such as placing calls or sending messages, for 3 months.
What are per-code rental services?
These services rent you a number for a few minutes to receive one code for one named app, then put the number back in the pool. You get no calls, no voicemail and no second code later.
That is the problem. Many accounts ask you to confirm your number again when you log in from a new device or reset a password. With a rented number, that later code goes to whoever has the number then. The account is yours until the first security check, and then it isn’t.
What does a paid app number give you?
A paid number is yours for as long as you pay. That one fact solves the main weakness of every free option: you can receive a code for the same account next month and next year.
The TripoSIM US Virtual Number costs $100 a year or $12.99 a month. It includes 300 outgoing minutes a month to the US and Canada, incoming calls, voicemail, and texts from US and Canadian senders. If your plan ends, the number is held for 30 days (yearly) or 90 days (monthly), then released.
It receives verification codes (OTP SMS) from apps, including WhatsApp and WhatsApp Business, so you can register and keep your accounts on it. TripoSIM tested 22 apps from October 3 to 18, 2026; that list shows examples, not a limit. It is an app-based VoIP number: it cannot send texts and there is no 911 calling. Our verification research and the guide to a US number for verification codes have the list and setup steps.
Which should you use?
- A throwaway sign-up, like a forum or a one-time coupon: free is fine. Avoid public inboxes even here if the account holds anything personal.
- You live in the US and have a US phone: Google Voice is worth trying first.
- An account you need to keep, such as email, payments, work or messaging: use a number that stays yours. A paid number is cheaper than losing access.
- You need a US number while living abroad: compare the options in how to get a US phone number from abroad, then check the two TripoSIM plans.
The simple test: if losing this number next month would lock you out of something you care about, don’t use a free one.