How it works
Using a free US number for SMS on ASMS takes three steps. First, browse the list of available US numbers on the United States page. Each number shows its area code and how recently it received a message, so you can pick one that looks active. Click the number to open its public inbox.
Second, go to whatever service or app you are signing up for and enter the US number exactly as shown, including the country code +1. Submit the verification request. The platform will send an SMS to that number within a few seconds.
Third, return to the ASMS inbox page and refresh. The incoming message will appear at the top of the list with its full text, sender, and timestamp. Copy the one-time code, paste it into the service, and you are done. The entire process typically takes under a minute.
Is it really free?
Yes, completely. There is no freemium timer, no credit system, and no signup wall hiding the messages. Every number listed under the US flag is genuinely shared and publicly readable, that is exactly what makes the zero-cost model work. The infrastructure is shared across many users rather than provisioned per individual, so the cost stays at zero for everyone.
The free model does come with one important characteristic: these are shared numbers. Other users can also see messages sent to the same inbox. That is by design. It means you should never use a shared ASMS number for anything sensitive, banking, personal accounts you care about, or anything where the content of the message needs to stay private. For those situations, ASMS offers private numbers as a paid upgrade, giving you an exclusive inbox no one else can read.
New US numbers are added regularly as demand grows. If every number in the list is receiving high traffic, or if a particular service has blocked a number due to prior use, check back, the inventory refreshes.
Privacy and security: what you should know
The privacy trade-off with shared numbers is clear-cut: you gain anonymity from the service you are verifying with, but you give up message confidentiality to the public inbox. Anyone who visits the same number page can read the same messages. This is the right tool for low-stakes verifications, social media accounts, marketplaces, trial signups, developer test environments, not for financial services or accounts tied to your real identity.
From a security standpoint, using a free US phone number for SMS protects your real mobile number from being added to marketing databases, sold to data brokers, or associated with accounts you may want to abandon later. Many users treat these numbers as a buffer between their personal SIM and the relentless tide of signup forms.
ASMS does not log IP addresses against message reads, does not require cookies for number browsing, and periodically wipes message histories to keep inboxes clean. The site runs over HTTPS on the same infrastructure that has powered the service since the AnonymSMS days.
Why use a US number specifically?
The United States has the largest concentration of English-language web services, SaaS products, e-commerce platforms, and app stores in the world. Many of these default to US phone verification even for international users, or only unlock the SMS verification flow when a +1 number is entered. Needing to receive SMS in the USA, and having a free US number ready, removes that geographic friction entirely.
Developers and QA engineers frequently need to test SMS flows against US numbers without spinning up paid Twilio or Vonage test accounts. A public ASMS number can receive those messages in a live environment at no cost, making it a genuinely useful option for staging and integration work. Because the inbox is web-based, there is no tooling to install on a CI machine.
International users also find US numbers valuable for accessing region-locked services, free trial periods tied to US phone verification, or platforms that simply behave differently when a +1 number is on the account. The ASMS stock covers multiple US area codes, so you are not limited to a single number that might be on a blocklist.
What can you verify with a US number?
The most common use cases for an American number for verification include: creating secondary accounts on social platforms such as Instagram, X (Twitter), TikTok, Facebook, and Snapchat; signing up for app store accounts on Google Play or the Apple App Store with a US identity; accessing free trials on streaming and SaaS platforms that require phone confirmation; registering on classified and marketplace sites such as Craigslist, eBay, or OfferUp; and testing OTP (one-time password) flows during software development.
Some services attempt to detect and block shared VoIP or virtual number ranges. When that happens, trying a different number from the ASMS US list often resolves it, the inventory spans multiple carriers and number blocks, so a single service blocklist rarely covers all of them. If a service categorically refuses virtual numbers, the ASMS private number tier uses numbers from different pools and is worth considering.
ASMS is not the right tool for verifying accounts where you need long-term, exclusive access to the number. WhatsApp, for example, ties your account permanently to the verified number and re-verifies it periodically. For ephemeral, one-time verification, the shared free numbers are exactly the right fit.
Other countries available
While US numbers are the most requested, ASMS maintains active number pools across a wide range of countries. UK numbers (+44) cover British-market services. German numbers (+49) serve a large share of EU-regulated platforms. Georgian, Ukrainian, Swedish, and other European numbers round out the coverage for region-specific needs. New countries are added based on demand, and the availability page lists every active country with its current number count.
For users who regularly work across multiple markets, developers, growth teams, international researchers, the ASMS API provides programmatic access to available numbers and message polling, removing the need to visit the site manually for each verification. The API documentation is at asms.ai/api-docs and covers both the REST endpoints and the native MCP server built for AI agent workflows.
API and private numbers: the premium tier
For teams and developers who need more than the shared inbox, ASMS offers a REST API and a native MCP server designed for AI agents and automated pipelines. The API lets you programmatically list available numbers, poll for incoming messages, and integrate SMS verification into CI pipelines or test suites without touching a browser. It is the same reliable infrastructure as the free tier, with rate limits and access controls appropriate for production use.
Private numbers give you an inbox only you can see, with a longer message retention window and the ability to reuse the number repeatedly without worrying that another user will intercept the code first. Both paid tiers are priced to be lightweight for individual developers and scalable for teams with heavier verification workloads.