No-KYC SMS Verification Glossary
Plain-language definitions of the terms used across SimSMS and the SMS-verification niche.
Clear definitions of the key concepts behind no-KYC SMS verification, virtual numbers and anonymous account creation.
- No-KYC
- No-KYC means a service requires no Know-Your-Customer identity verification — no government ID, no name, no proof of address. SimSMS is no-KYC at every step.
- SMS verification
- SMS verification is the process of confirming an account by entering a one-time code sent by text message to a phone number. A virtual number from SimSMS receives that code without using your personal SIM.
- OTP (One-Time Password)
- An OTP is a single-use numeric code, usually 4–8 digits, sent by SMS to authenticate a login or registration. It expires after one use or a short time window.
- Virtual phone number
- A virtual phone number is a real, dialable number not tied to a physical SIM in your possession; it receives SMS in the cloud. SimSMS issues virtual numbers in 190+ countries.
- Non-VoIP number
- A non-VoIP number is issued by a real mobile carrier rather than an internet calling app. Many services block VoIP numbers, so non-VoIP (physical/premium) numbers have higher acceptance.
- Seed phrase authentication
- Seed-phrase authentication replaces email and password with a single secret phrase generated at signup. On SimSMS that phrase is your only credential — there is no account recovery if it is lost.
- 番号レンタル
- A number rental is a dedicated virtual number kept for a fixed period (7, 14, 30 or 90 days on SimSMS) that receives unlimited incoming SMS for the whole window, unlike a one-time activation.
- Virtual / physical / premium operators
- Operator tiers describe where a number comes from: virtual numbers are app-issued and cheapest, physical numbers come from real carriers (about 1.4–2.0× the base price), and premium numbers have the highest delivery success (about 2.5–4.0×).
- Crypto-only payment
- Crypto-only payment means a service accepts cryptocurrency exclusively and no cards or bank transfers. SimSMS accepts 20+ coins including Bitcoin, Monero, Ethereum, USDT and USDC.
- Auto-refund
- Auto-refund means the cost of a number is returned to your balance automatically if the expected SMS never arrives, so you only pay for codes that are actually delivered.
- MCP (Model Context Protocol)
- MCP is an open standard that lets AI assistants call external tools. SimSMS runs an MCP server at simsms.co/mcp so agents can buy numbers and read SMS codes directly.
- x402
- x402 is an HTTP-native payment standard that lets a client settle a request with cryptocurrency. SimSMS supports gasless x402 USDC top-ups on Base for AI-agent payments.