The app wants to confirm that “the number the user entered is the phone number of the phone they have.” When the phone connects over the mobile network, the operator can compare the numbers directly, with no SMS verification code needed.
The number entered in the app matches the phone number on the SIM card in the phone.
The number is off by one digit, so the operator’s response is a mismatch.
The app gets this phone’s phone number directly from the operator, with no need for the user to enter it.
A and BThe comparison happens within the operator network. The response only indicates a match or mismatch.
CTo skip manual entry, use “Get phone number” to have the operator return it directly.
Number Verification: How it works
- Connect to the mobile networkThe user opens the app using the phone’s mobile data, allowing the operator network to recognize the phone.
- Send the numberThe app sends the phone number to compare, either as plain text or as a SHA-256 hash.
- Return the resultThe operator returns whether the numbers match, or returns this phone’s phone number directly.
Number Verification: API spec
POST /verify compares phone numbers; GET /device-phone-number retrieves the phone numberphoneNumber (plain text) or hashedPhoneNumber (SHA-256 hash)| Response fields | Meaning | Example |
|---|---|---|
| devicePhoneNumberVerified | Whether the submitted number matches the phone’s phone number | true |
| devicePhoneNumber | This phone’s phone number (E.164 format) | +886912345678 |
Responses for three scenarios (excerpts)
trueMatches the phone number on the SIM cardfalseDoes not match the phone number on the SIM card+886912345678This phone’s phone numberSpec source: CAMARA NumberVerification r3.2 (Number Verification v2.1.0)
Number Verification: GSMA use cases
Reducing fraudulent online ticket purchases
Problem to solveOnline ticket sales for popular events often face fraudulent purchases, affecting fairness and the buying experience.
Number Verification's roleVerifies that buyers have the corresponding phone when purchasing tickets to prevent fraudulent purchases.
Used together: SIM Swap
GSMA source ↗Connected and Validated delivery services
Problem to solveDeliveries of high-value or regulated items require identity checks for couriers and recipients, along with real-time tracking.
Number Verification's roleUses phone numbers to verify couriers and recipients.
Used together: Location Verification, SIM Swap, Quality on Demand
GSMA source ↗Online Ticketing Protection
Problem to solvePrevents bots from bypassing online queues and buying large numbers of tickets for resale.
Number Verification's roleVerifies that the buyer has the phone number to limit bulk purchases.
Used together: Device Identifier, Know Your Customer Match
GSMA source ↗Detection of Bot Traffic
Problem to solvePrevents fraud such as fake clicks that inflate advertising metrics.
Number Verification's roleVerifies that network access comes from a real phone rather than a cloud server.
Used together: Device Identifier
GSMA source ↗Frictionless identity verification for fraud prevention
Problem to solveVerifies identity at critical moments, such as when customers change their details, to prevent identity fraud.
Number Verification's roleVerifies that the customer has the new phone number they want to link to their account.
Used together: Know Your Customer Match
GSMA source ↗Seamless authentication for device binding
Problem to solveSecurely and seamlessly links an account to a phone number during registration or when switching to a new phone.
Number Verification's roleThe operator verifies that the user has this phone number.
GSMA source ↗Seamless authentication during password reset
Problem to solveProtects the password reset process.
Number Verification's roleVerifies that the user has the phone number linked to the account.
GSMA source ↗Seamless authentication for two-factor authentication
Problem to solveAdds two-factor authentication without extra effort for the user.
Number Verification's roleThe operator verifies that the user has this phone number as a second authentication factor.
GSMA source ↗Seamless Authentication for Passwordless Login
Problem to solveLets returning users log in directly with their phone number.
Number Verification's roleVerifies that the user has this phone number in place of a password.
GSMA source ↗GSMA case studies (14)
- Banco Daycoval
- China Telecom
- LankaPay
- BRI Bank
- Easy Buy
- VIRe
- OTP Banka
- Tiger Brokers
- ABA Bank
- Cabify
- Lydia
- TIM Brasil
- Telkomsel
- Singtel
Sources: GSMA Open Gateway Use Case Library and API Descriptions (accessed 2026-10-14). Descriptions are summaries.