Configure NumCheckr Disposable Phone Detection

Blacklist Manager Premium sends a normalized phone number to NumCheckr to detect disposable, virtual, burner, and public-SMS-gateway numbers. The current enforcement decision is based on the provider’s is_disposable result.

Open the feature

Go to Blacklist Manager > Settings > Integrations > NumCheckr API token. The disposable-phone protection must also be enabled in the applicable Blacklist Manager settings.

Create and save the token

1. Create a NumCheckr account and generate an API token.
2. Save the token in Blacklist Manager. It is a secret Bearer credential and must not appear in screenshots, logs, or client-side code.
3. Confirm the account has API access and sufficient current quota.

Use international phone data

Provide customer phone numbers with a country code in E.164 form where possible, such as +14155552671. The plugin normalizes formatting before the request, but a missing country code can make an otherwise valid number ambiguous.

Test and roll out

1. Test a representative legitimate mobile number and a provider-approved disposable test number on staging.
2. Confirm only is_disposable: true triggers the disposable-phone block path.
3. Review active-line, carrier, country, and line-type fields as supporting context, not proof of identity.
4. Monitor false positives before applying direct blocking broadly, especially for VoIP and privacy-oriented customers.

Failure behavior

• Missing/invalid tokens, quota failures, timeouts, and invalid JSON are API errors and should be investigated separately from a non-disposable result.
• Provider availability changes must not be interpreted as evidence that a phone number is safe.
• Keep a recovery path for legitimate customers who cannot use another number.

Privacy and documentation stability

The customer phone number is sent to NumCheckr. Review the provider privacy terms before enabling the integration. NumCheckr currently documents the public endpoint and Bearer-token request in an official implementation guide rather than a versioned API reference, so use the provider link below as the current contract and re-verify it during plugin releases.

Official provider documentation

• NumCheckr phone-validation API guide
• NumCheckr service overview

Provider documentation and commercial terms can change. These links were verified on August 3, 2026.