China is a highly regulated "ANI Sensitive" (Automatic Number Identification) destination. To combat international telecom fraud, Chinese carriers use sophisticated AI-driven filters to block any traffic that appears automated, faked, or non-human.
Key Update (January 2026):
Under the Amended Cybersecurity Law, penalties for "illegal routing" or faking Caller ID have increased significantly. Carriers are now legally required to block any outbound call that does not originate from a verified, genuine user.
Dialing Formats
Always ensure numbers are formatted correctly to pass through international gateways.
Mobile Format:
86 1XX XXXX XXXX(11 digits after country code)Landline Format:
86 <Area Code> XXXX XXXX(Area codes are 2-3 digits)
Strict Prohibitions (The "No-Go" List)
The following call types are strictly blocked by in-country carriers and are beyond our technical scope to "unblock":
China-to-China Local Mimicry: You cannot use a Chinese (+86) Caller ID to call a Chinese number from outside the country (CLI Spoofing).
Dialer/Robocalling: High-volume, automated dialing is flagged instantly.
Testing Tools/APIs: Automated testing pings are recognized as "non-genuine" traffic and blacklisted.
Invalid ANI: Any Caller ID that is not a valid, reachable phone number.
Unregistered Marketing: Cold calling without explicit prior consent (PIPL compliance) is blocked at the gateway level.
Why Calls Fail (Carrier Logic)
| Symptom | Cause |
| Instant Drop | The CLI (Caller ID) is on a global blacklist or the format is invalid. |
| "User Busy" / Constant Rejection | The frequency of calls from your IP/Number has triggered an anti-fraud threshold. |
| One-Way Audio | In-country security firewalls are inspecting the packet for "non-conversational" signatures. |
Best Practices for Compliance (2026)
To ensure your customers' calls actually reach China, they must follow these rules:
Use Verified CLI: Only use a legitimate, registered business number as the Caller ID.
Human-to-Human Only: Calls must be "conversational." If a carrier detects a recording or a bot at the start of the call, the route will be killed.
KYC Requirements: All users must have up-to-date Know Your Customer (KYC) documentation on file. Carriers now perform periodic audits of the "Use Case" for the numbers being used.
Avoid "Bursty" Traffic: Do not make 100 calls in 5 minutes and then stop. This pattern mimics fraud bots.
How to Explain This to Customers
"Due to strict telecom regulations enforced by the Chinese Ministry of Industry and Information Technology (MIIT), all outbound calls to China are monitored for 'genuine user' signatures.
If you are using automated dialers, testing scripts, or unverified Caller IDs, the calls will be blocked by the local Chinese carriers. This is a regulatory 'in-country' restriction designed to prevent fraud and is not a technical fault of the service provider."
Escalation Path
Step 1: Verify the customer is dialing in E.164 format.
Step 2: Confirm the customer is not using an automated dialer.
Step 3: If the call still fails, check if the **
