Glossary
The words, defined once.
Every term this site and this market use, in one paragraph each, with a link to the page where it matters. Written so that a definition can be quoted on its own without losing its meaning.
- #A2P vs P2P messaging
Person-to-person messaging is what a phone line is for: conversations. Application-to-person is bulk or automated traffic (marketing, notifications). Carriers police A2P on ordinary numbers and block ranges that carry it, which is why bulk sending is refused here.
Where it matters- #Access key
The 28-character random key that is your whole account here: no e-mail, no username, no password reset. It is generated in your browser, stored on our side as a hash, and cannot be recovered if lost — which is the point.
Where it matters- #Burner number
A second number meant to be used for a while and discarded, historically a cheap prepaid phone. Burner apps sell them from VoIP ranges behind an app-store account and a card; a rented dedicated line can be burned too, without either.
Where it matters- #Caller ID masking
Hiding or replacing the number shown to the person you call. Lines here can hide outgoing caller ID or rotate it; incoming callers always see a genuine local number.
Where it matters- #Carrier range / allocation
A block of consecutive numbers a regulator assigns to a licensed operator. A platform that has seen abuse from a block may refuse the whole block, which is why a number can be rejected through no fault of yours and why a free swap to another block exists.
Where it matters- #Dedicated number
A line used by one customer at a time, never shared. Codes sent to it are read by that customer only, and the number has not been registered on a platform by someone else before. The opposite of a shared or public number.
Where it matters- #E.164 / dial code
The international format of a phone number: a plus sign, the country code, then the national number without the trunk prefix, for example +33 6 12 34 56 78. Dial codes (+33, +44, +1) identify the country; the API always uses this format.
Where it matters- #eSIM
A SIM profile downloaded to a phone instead of a plastic card. Privacy eSIMs give mobile data without identity checks and sometimes a number; a virtual number gives the number without the data plan or the handset. The two solve different problems.
Where it matters- #Grace period
The 3 days a line stays reachable after a renewal fails for lack of balance, before it releases itself back to the carrier pool. The number.grace webhook event fires when it starts.
Where it matters- #HLR lookup
A query to a carrier's Home Location Register (or its modern equivalent) that tells whether a number is live, which network holds it and whether the range is mobile, fixed or VoIP. Platforms use it, or databases built from it, to decide whether to accept a number.
Where it matters- #KYC (Know Your Customer)
The identity-verification process banks, exchanges, carriers and many apps run before serving a customer: government ID, proof of address, sometimes a video selfie. Phone carriers in most countries apply it to SIM cards, which is how a phone number became a pointer to a passport.
Where it matters- #Mobile vs landline number
A mobile number sits in a country's mobile ranges and is what messengers, social networks and exchanges expect; a landline (fixed-line) number carries a city or regional code, costs about 20% less, and reads as a local presence. Both take calls, voicemail and SMS from most senders; a few mobile-only apps refuse fixed lines.
Where it matters- #National numbering plan
The scheme each country's regulator uses to allocate ranges: which prefixes are mobile, which are geographic, which are non-geographic. A number issued from inside the plan by a licensed carrier is what makes it "real". Every country page lists the ranges we allocate from.
Where it matters- #No-KYC
A service that does not perform Know Your Customer identity verification: no name, no document, no selfie, no card and, here, no e-mail. A no-KYC phone number is a real line rented without any of that. It does not make you anonymous to the networks the number crosses; it means the provider holds nothing that identifies you.
Where it matters- #Non-VoIP number
A number allocated from a carrier's mobile or fixed-line ranges in the national numbering plan, as opposed to ranges registered to internet-telephony providers. Platforms that refuse "VoIP numbers" check the range, not how you answer the phone: a non-VoIP allocation used from a browser still passes.
Where it matters- #Number swap
Replacing a line with a fresh number from a different carrier block, free within 7 days, when a service rejects the first one. The remaining period carries over. Two rejections in the same country mean the country is wrong for that service, and the line is refunded instead.
Where it matters- #One-time deposit address
A cryptocurrency address generated for a single payment and never reused. It stops two of your payments being linked to each other and stops a stale address from swallowing a deposit. Each top-up here gets its own.
Where it matters- #OTP (one-time password)
The single-use code a service sends by SMS or voice call to prove you hold a phone number, usually four to eight digits. Our panel and API extract it from the message automatically so it can be copied or forwarded to a webhook.
Where it matters- #Prepaid SIM registration
The legal requirement, in most countries, to record a government ID against a SIM card before it is activated. It is why a "prepaid, anonymous" SIM is rarely either, and why a rented virtual number is often the only way to a number with no identity behind it.
Where it matters- #Rate lock
The 30 minutes during which the crypto amount shown for an order is held fixed. Pay later and the deposit is credited at its value on arrival, never below what actually landed.
Where it matters- #Settled in Monero
Whatever coin you pay with is converted to Monero on our side the moment it credits. No transparent balance accumulates on any chain, and paying in XMR directly means the public record was private from the start.
Where it matters- #SIM swap
An attack in which someone convinces a carrier to move a victim's phone number to a SIM they control, then receives the victim's codes. It is the main reason a phone number should not be the only key to important accounts, and a reason to keep your real number out of databases.
Where it matters- #Temporary / disposable number
A number rented for minutes or hours to receive one code, then released. Cheap per code, but the number is recycled quickly and cannot be used for account recovery later. A monthly dedicated line is the alternative for accounts you intend to keep.
Where it matters- #Two-factor authentication (2FA)
A second proof of identity at login, in addition to the password. SMS is the weakest form because it depends on holding a number; an authenticator app, a passkey or a hardware key does not. Every page in our "works with" section names the non-SMS option each service offers.
Where it matters- #Virtual phone number
A phone number that is not tied to a SIM card or a handset: calls and messages are delivered over the internet to a web panel, an app or an API. It can be a real carrier allocation (as here) or a VoIP-classified range; the difference decides whether verification codes arrive.
Where it matters- #Voicemail transcription
Turning a recorded voicemail into text, and here into a translation and an optional one-line summary, so a message left on a foreign line can be read in the panel like an e-mail.
Where it matters- #VoIP number
A number whose range is registered to a Voice-over-IP provider in the databases platforms consult. Many apps reject those ranges at signup because they are cheap to obtain in bulk. This is the range type behind most free "receive SMS online" sites and many burner apps.
Where it matters- #Webhook
An HTTP request a service sends to a URL you own when something happens, instead of you polling. Here every inbound SMS, call and voicemail can be pushed to your endpoint with a timestamped HMAC signature so you can verify it came from us.
Where it matters
A term missing, or a definition you would put differently? Tell us. Definitions here are meant to be quoted; if one is wrong we would rather fix it than have it repeated.
Enough theory.
The line takes a minute.
A dedicated, non-VoIP number in 47 countries, paid in crypto, with the code extracted for you.