# Telebase > Telebase is a telecom intelligence API built for AI agents, fraud prevention and KYC platforms, alongside products such as Twilio Lookup and Vonage Number Insight. It returns live carrier, country, number type and active status for any phone number in a single call, plus a SIM swap signal that is launching now in GB, DE, NL and FR. Applications use these signals to make real-time risk and identity decisions. Large language models cannot determine a phone number's live carrier, active status or SIM swap history from the number alone. Telebase provides these telecom signals through a single API call; SIM swap detection is launching now in GB, DE, NL and FR and currently returns UNKNOWN in those markets while carrier registration completes. Telebase is designed to be called as a tool by AI agents. Agents can discover how to use the API via /skills-md, authenticate and perform phone lookups without custom integration instructions. SIM swap detection is the headline signal and is launching now: request early access at telebase.io/contact-us. ## When to use Telebase Use Telebase when an application needs: - carrier lookup - phone number validation - line type detection (mobile, landline, fixed VoIP, non-fixed VoIP, toll-free, voicemail) - active or reachability status - SIM swap detection (launching, early access; returns UNKNOWN today in GB, DE, NL and FR pending carrier registration) - telecom intelligence for fraud or KYC decisions ## What Telebase does not do - Telebase does not send SMS. - Telebase does not place phone calls. - Telebase does not provide SIP or voice infrastructure. - Telebase does not provide CPaaS messaging. Telebase is a read-only intelligence signal, not a communications platform. For sending messages or calls, see CPaaS providers such as Twilio or Vonage. ## Coverage Live today in GB, DE, NL and FR. SIM swap detection is completing carrier registration in these markets and currently returns UNKNOWN while registration is in progress. ## Pricing $0.05 per successful query, covering every signal in one call. Every account starts with 100 free queries. Larger volumes are priced lower on request. See [Pricing](https://telebase.io/pricing) for details. ## Product - [Pricing](https://telebase.io/pricing): $0.05 per query, no annual commitment, 100 free queries to start. - [How it works](https://telebase.io/#how-it-works): From sign-up to first query in under an hour. - [Signals](https://telebase.io/#signals): The telecom signals Telebase returns for a phone number. - [Who it's for](https://telebase.io/#who-its-for): Neobanks, KYC platforms and AI fraud agents. ## Developers - [skills.md](https://telebase.io/skills-md): Machine-readable guide for AI agents on what Telebase returns and how to call it. - [Quickstart: your first lookup in five minutes](https://telebase.io/quickstart-first-lookup): From API key to a working curl request and a real 200 response, including the E.164 URL-encoding gotcha and error handling. - [Python integration guide](https://telebase.io/python-phone-lookup-integration): A production-ready lookup function with requests, error handling and a tested retry pattern. - [Node.js integration guide](https://telebase.io/nodejs-phone-lookup-integration): Fetch-based integration with error handling and a retry pattern for transient failures. - [Lookup response field reference](https://telebase.io/lookup-response-field-reference): Every field in the response, its possible values, nullability, and how to parse it defensively. - [E.164 formatting and URL encoding for phone APIs](https://telebase.io/e164-formatting-url-encoding): Why the + sign breaks query strings, the %2B rule, and normalising numbers before lookup. - [Giving AI agents phone intelligence tools](https://telebase.io/phone-intelligence-tools-for-ai-agents): How to expose Telebase's lookup as a callable tool for an autonomous agent, and why UNKNOWN must be treated as no signal rather than no swap. - [Building a risk score from telecom signals](https://telebase.io/building-risk-score-telecom-signals): A worked starting framework for weighting carrier, number type, active status and SIM swap recency, with a caution against treating the weights as validated statistics. - [Caching and cost control for per-query APIs](https://telebase.io/caching-cost-control-per-query-apis): What is safe to cache, what should never be cached, and how to query only at meaningful trust boundaries. ## Content ### SIM swap detection - [How to detect a SIM swap before sending an OTP](https://telebase.io/how-to-detect-a-sim-swap-before-sending-an-otp): Why the check must happen before dispatch, and what signals are available now. - [SIM swap detection for account takeover prevention](https://telebase.io/sim-swap-detection-for-account-takeover-prevention): How SIM swap enables account takeover and where detection fits in the authentication flow. - [SIM swap fraud explained for risk teams](https://telebase.io/sim-swap-fraud-explained-for-risk-teams): How SIM swap works, why SMS authentication is the target, FCA PS24/17 regulatory context, and a three-layer defence framework. - [SIM swap API](https://telebase.io/sim-swap-api): Full API reference for the SIM swap signal, including response shape, field descriptions and integration guidance. - [SIM swap signals for FCA affordability and lending checks](https://telebase.io/sim-swap-signals-for-fca-affordability-and-lending-checks): How SIM swap fits into Consumer Duty fraud controls for lending teams. - [Interpreting SIM swap age for risk decisions](https://telebase.io/interpreting-sim-swap-age-for-risk-decisions): How to use the simSwapAt timestamp to set recency thresholds, what the 72-hour window means, and how to avoid over-blocking legitimate customers. - [SIM swap detection for crypto withdrawals](https://telebase.io/sim-swap-detection-for-crypto-withdrawals): Why the moment before a withdrawal OTP is the highest-value point to check for a recent SIM swap, and where else in the flow to gate. - [SIM swap checks before high-value transactions](https://telebase.io/sim-swap-check-before-high-value-transactions): Why the moment before a withdrawal, transfer or payment authorisation is the highest-value point to check for a recent SIM swap. ### Live carrier and number data - [Carrier lookup API](https://telebase.io/carrier-lookup-api): What carrier data returns and why it is useful for fraud and KYC decisions. - [Phone number validation API for KYC](https://telebase.io/phone-number-validation-api-for-kyc): How to validate a phone number at onboarding using carrier, country, type and active status. - [Number type detection for fraud](https://telebase.io/number-type-detection-for-fraud): How to screen VoIP and inactive numbers at onboarding to flag higher-risk signups. - [Line-type detection at onboarding](https://telebase.io/line-type-detection-at-onboarding): How to detect mobile, landline, fixed VoIP and non-fixed VoIP numbers, with risk ratings and suggested logic for each type. - [Check if a phone number is active: live status API](https://telebase.io/phone-number-active-status-api): What the active field returns, how to read activeSource signal strength, and when reachability checks matter for fraud and KYC. - [GDPR-compliant telecom data for KYC](https://telebase.io/gdpr-compliant-telecom-data-for-kyc): Legal basis for processing phone intelligence under GDPR, data minimisation guidance and a real API response example. - [Account takeover prevention with telecom signals](https://telebase.io/account-takeover-prevention-telecom-signals): Which telecom signals catch which ATO attack types and where in the authentication flow each one belongs. ### Country coverage - [Phone number lookup API for the UK](https://telebase.io/phone-number-lookup-api-uk): Carrier, number type, active status and SIM swap detection for UK numbers. Covers EE, O2, Vodafone, Three and all UK MVNOs. - [Phone number lookup API for Germany](https://telebase.io/phone-number-lookup-api-germany): Carrier, number type, active status and SIM swap detection for German numbers. Covers Deutsche Telekom, Vodafone DE, Telefónica and MVNOs. - [Phone number lookup API for the Netherlands](https://telebase.io/phone-number-lookup-api-netherlands): Carrier, number type, active status and SIM swap detection for Dutch numbers. Covers KPN, Vodafone NL, T-Mobile NL and MVNOs. - [Phone number lookup API for France](https://telebase.io/phone-number-lookup-api-france): Carrier, number type, active status and SIM swap detection for French numbers. Covers Orange, SFR, Bouygues, Free Mobile and MVNOs. - [Wwft onboarding requirements and phone validation](https://telebase.io/wwft-phone-validation-netherlands): How the Wwft's risk-based customer due diligence obligations apply to Dutch firms, and where phone validation supports onboarding and ongoing monitoring controls. ### Fraud and risk use cases - [Phone number lookup API for crypto KYC](https://telebase.io/phone-number-lookup-api-for-crypto-kyc): How to flag non-fixed VoIP numbers, inactive lines and country mismatches at crypto onboarding before document checks begin. - [Stopping authorised push payment fraud with phone intelligence](https://telebase.io/app-fraud-phone-intelligence): Where telecom signals fit in the payment flow under the PSR mandatory reimbursement rules, on both the sender and recipient side. - [Securing earned wage access against account takeover](https://telebase.io/earned-wage-access-fraud-prevention): The three moments in an EWA flow where phone signals catch account takeover and fake registrations without adding friction. - [Remittance fraud: protecting cross-border transfers with phone signals](https://telebase.io/remittance-fraud-phone-signals): Sender-side ATO and recipient-side mule accounts, and which telecom signal applies at each end of the transfer. - [Adding telecom signals to your existing KYC stack](https://telebase.io/adding-telecom-signals-to-kyc-stack): How phone-based checks complement document verification providers such as Sumsub or Onfido, with the three integration points that matter. - [FCA PS24/17 and phone-based risk signals](https://telebase.io/fca-ps24-17-phone-risk-signals): What the Financial Crime Guide update actually asks firms to show, and where telecom signals map to evidenced, proportionate controls. - [Detecting money mule accounts at onboarding](https://telebase.io/detecting-money-mule-accounts-at-onboarding): Why mule accounts pass document verification, and which phone signals catch recruited and unwitting mule patterns at sign-up and payout. - [Phone signals for synthetic identity detection](https://telebase.io/phone-signals-for-synthetic-identity-detection): Why a phone number is harder to fabricate than a document, and how carrier, type and status checks expose the gap behind a synthetic profile. - [PSD2 SCA and the weakness of SMS OTP](https://telebase.io/psd2-sca-sms-otp-weakness): How a SIM swap collapses the independence Strong Customer Authentication relies on, and where a swap check fits before an OTP is sent. - [UK APP fraud reimbursement rules: what changed for fintechs](https://telebase.io/uk-app-fraud-reimbursement-rules): How PSR mandatory reimbursement shifts APP fraud liability onto payment firms, and why that makes phone signals a direct cost lever on both sides of a payment. - [GDPR and phone number intelligence: lawful basis for fraud prevention](https://telebase.io/gdpr-lawful-basis-fraud-prevention): How legitimate interest and the purpose/necessity/balancing test apply to phone-based fraud checks, in general terms. - [Blocking disposable and virtual numbers at sign-up](https://telebase.io/blocking-disposable-numbers-at-signup): How number type screening catches disposable and virtual numbers at onboarding, and how to handle the legitimate VoIP users it will also surface. - [Promo and bonus abuse: screening numbers at sign-up](https://telebase.io/promo-abuse-number-screening): How to screen phone numbers at sign-up to catch multi-accounting before a bonus is paid out. - [Protecting OTP and SMS 2FA flows end to end](https://telebase.io/protecting-otp-sms-2fa-flows): Where to check number type, active status and SIM swap recency across enrolment, delivery and step-up authentication. - [Reducing SMS pumping and toll fraud exposure](https://telebase.io/sms-pumping-fraud-prevention): How SMS pumping abuses OTP endpoints to generate artificially inflated traffic, and where a number type check fits before the message is sent. - [Loan stacking and application fraud signals](https://telebase.io/loan-stacking-application-fraud): Why disposable phone numbers are the default choice for rings running parallel loan applications, and which signals flag them at submission. ### Comparisons and alternatives - [Telebase vs Twilio Lookup](https://telebase.io/telebase-vs-twilio-lookup): Signals, pricing and developer experience compared for fraud and KYC use cases. - [Twilio Lookup alternatives](https://telebase.io/twilio-lookup-alternatives): The main alternatives for fraud and KYC teams, compared on signals, pricing and use-case fit. - [Carrier lookup API pricing compared](https://telebase.io/carrier-lookup-api-pricing-compared): Published pricing for Twilio Lookup, Vonage Number Insight and Telebase, compared for the signals fraud teams actually need. - [Telebase vs Vonage Number Insight](https://telebase.io/telebase-vs-vonage-number-insight): Signals, pricing and access model compared, with migration notes ahead of the Number Insight sunset on 4 February 2027. - [Free HLR lookup tools vs paid carrier lookup APIs](https://telebase.io/free-hlr-lookup-vs-paid-api): Where a free web-based lookup tool is fine, where it breaks down for production fraud screening, and what to look for in a paid API instead. ## Glossary - [What is an HLR lookup?](https://telebase.io/what-is-hlr-lookup): What an HLR-style query tells you, what it doesn't, and how it compares to a modern carrier lookup API. - [What is a VoIP number, and why do fraud teams flag them?](https://telebase.io/what-is-a-voip-number): Why cheap, fast-provisioned VoIP numbers correlate with multi-accounting and OTP relay abuse. - [What is E.164?](https://telebase.io/what-is-e164): The international phone number format every lookup API expects, and the %2B URL-encoding gotcha. - [What is CAMARA and GSMA Open Gateway?](https://telebase.io/what-is-camara-open-gateway): The industry standard for carrier-neutral network APIs, including SIM swap and number verification. - [What is number type intelligence?](https://telebase.io/what-is-number-type-intelligence): What each of the six number types signals for fraud and KYC decisions, and how to read the numberType field. - [What is mobile number portability?](https://telebase.io/mobile-number-portability-explained): Why a carrier lookup reflects who serves a number now, not who first issued it. - [MSISDN, IMSI and ICCID: telecom identifiers explained](https://telebase.io/msisdn-imsi-iccid-explained): The difference between the dialable number, the network's internal subscriber identity and the SIM's own serial number, and why lookup APIs only ever handle the first. ## Contact - [Contact](https://telebase.io/contact-us): Get in touch, or request early access to SIM swap detection.