What ASMS.ai offers if you are comparing sites like 5sim
The /otp page sells private numbers one code at a time, from $0.50. You choose the service you are verifying, see its exact price and stock, and pay from your wallet. Two pools are on sale: VoIP High Quality (US, +1), which is the cheapest, and United Kingdom (+44), which uses real UK mobile numbers.
The /numbers page rents dedicated non-VoIP numbers from $4.99, for 1 day up to 12 months depending on the country, with unlimited SMS. A rental is the right choice for an account you plan to keep, because you may need the same number again for a login or recovery.
The free numbers sit alongside both. They are public, cost nothing, and suit a quick, low-stakes code.
The ASMS.ai API: what a 5sim API user will look for
If you searched for 5sim api, you probably want to order numbers and read codes from your own code. The ASMS.ai REST API covers that flow: check your balance, list services and prices, order a number, then poll for the SMS. Authentication is a single API key.
Charges come out of the same wallet you use on the website, so there is no separate plan or invoice to manage. The automatic refund applies when no code arrives, whether you ordered in the browser or through the API.
A sensible way to start is to place one order by hand on the /otp page, so you see the price and stock for your service, then automate the same order through the API. Moving from another provider means changing endpoints and the key, not your whole flow: order, wait, read.
An MCP server for AI agents
MCP (Model Context Protocol) lets an AI assistant or agent call tools directly. ASMS.ai runs a native MCP server, so an agent can order a number, wait for the SMS and read the code without a person clicking through the site. It uses the same API key and wallet.
This is useful for testing your own sign-up flows, QA runs that need a real code, and agents that complete a verification step you have asked them to do. Use it on services where you are allowed to, and within their terms.
Looking for a 5sim free number? How free works here
ASMS.ai has free numbers you can use with no account at all. They are shared, so the inbox is public: anyone opening the same number can read what arrives. Most are UK numbers, with Netherlands, Finland and a few other countries.
Because shared numbers are used by many people, a big app may say the number is already taken or refuse it. That is normal for any public number. If a free number fails, a private per-code number is the next step, and it costs nothing if the code never comes.
Never use a free number for an account that protects money or that you want to keep. Whoever can read the number's texts can receive its reset code.
What to compare when choosing an SMS verification service
Refunds: what happens when a code never arrives. On ASMS.ai the order is refunded automatically. Inbox privacy: whether only you can read the messages. Our paid numbers have private inboxes; free ones are public.
Number types: whether you can choose between VoIP and non-VoIP. Some services reject VoIP, so the honest ladder is VoIP High Quality first, a UK number next, then a non-VoIP rental for strict services.
Developer access: a REST API, an MCP server for agents, and how billing works. Payment methods: check which ones the service takes; ours are listed on the top-up page. Support: how you reach a person when something goes wrong. Track record: how long the service has been running. Ours has been online since 2018.
How to switch to ASMS.ai
Create an account, then top up your wallet. Open the /otp page, choose the service and pool, check the price and stock, and place the order. Enter the number on the service, and read the code on the order page when it arrives.
For automation, generate an API key in your dashboard and repeat the same steps through the API or the MCP server.