Our SMS pools, explained
VoIP High Quality is a pool of US numbers with the +1 country code. It is the cheapest option and the right first try for most services that accept internet numbers.
The United Kingdom pool uses real UK mobile numbers with +44. Use it when a service is UK based, wants a +44 number, or turned down the US pool.
Rentals on the /numbers page are dedicated non-VoIP numbers, from $4.99, for 1 day up to 12 months depending on the country. They are for strict services that refuse VoIP, and for any account you want to keep, since the number stays yours for the whole period.
Picking a pool for your service
On the /otp page, choose the service first. You then see each pool's price and stock for that service, so you can pick before you pay.
A simple rule: start with VoIP High Quality, because a code that never arrives is refunded and costs you nothing. If the service rejects it, try the UK pool. If both fail, the service probably wants a non-VoIP number, and a rental is the next step. For a rental, you can cancel between 5 and 120 minutes after renting, before any SMS arrives, for a refund.
SMSPool free number searches: our free numbers
If you were looking for an SMSPool free number, the free option on ASMS.ai is a list of shared numbers you can use with no account. Most are UK numbers, with Netherlands, Finland and a few other countries.
The inbox on a shared number is public. That is what keeps it free, and it is also why big apps often reject shared numbers or say they are taken: many people have used them before.
Use a free number for a one-off, low-stakes code. Never use one for two-factor login, recovery or anything tied to money, because whoever reads the number's texts can receive the reset code.
Private inbox or public inbox
Every paid number on ASMS.ai has a private inbox. Only you see the code, on your order or rental page, and it is not listed anywhere public.
That matters more than it sounds. A code sent to a public inbox can be read by anyone who opens that number at the same moment. For anything you care about, a private number is the right default.
A rental goes one step further. The inbox stays private for the whole rental period, and every SMS that arrives on the number lands there, so you can come back for a login code or a recovery code weeks later. That is why we recommend a rental for any account you plan to keep using.
What to compare when choosing an SMS verification service
Ask what happens when a code fails: here, per-code orders are refunded automatically. Ask who can read the inbox: our paid numbers are private, our free ones are public. Ask whether you can choose VoIP or non-VoIP, since some services accept only one.
If you build software, check for an API and an MCP server for AI agents. ASMS.ai has both, with one API key and wallet billing. Check the payment methods each service accepts; ours are on the top-up page.
And check the basics: how you contact support, and how long the service has been running. ASMS.ai has been online since 2018.
How to switch to ASMS.ai
Create an account and top up your wallet. On the /otp page, pick your service, compare the pools, and order a number. Enter it on the service and read the code on your order page.
For an account you plan to keep, rent a number on the /numbers page instead, so you can receive codes on it again later.
Developers can do the same through the REST API or the MCP server: generate an API key in your dashboard, and orders are paid from the same wallet.