Tencent Billing System (Mi Master): Architecture, Reliability, Security, and Global Capabilities

In this presentation, Tencent billing architect Duan Kexiao introduces the Mi Master billing platform, which has been open as a SaaS service since April. The platform handles the settlement of all Tencent revenue (735 billion RMB in Q1) and powers major products such as Honor of Kings, PUBG, Cloud services, WeChat Mini‑Program payments, and QQ Wallet.

The billing system has evolved over 15 years through stages of carrier billing, cloud payment, mobile payment, and open platforms. It now primarily serves mobile payment scenarios (WeChat Pay, Alipay, etc.).

1. System Architecture Overview – A unified payment entry point routes requests to the nearest node, performs network routing, disaster‑recovery, and risk control checks. After successful deduction, transactions are persisted to a distributed database with multi‑master/backup topology. The system consists of three major components: online transaction processing, data services (user profiling, recommendation), and an operations platform. The architecture is modular and layered, supporting vertical and horizontal extensions, sandbox/whitelist gray‑release, and can be deployed across multiple data centers.

2. Transaction Reliability Guarantees – To handle timeout or missing notifications, the platform delegates control to an order center, degrading synchronous requests to asynchronous processing, and eventually to offline batch reconciliation to ensure consistency. Cross‑region deployment (two‑site, six‑center) with a self‑developed financial‑grade database provides high availability. Traffic spikes are mitigated through scenario‑based SET isolation, incremental load testing during low‑traffic windows, and rapid scaling.

3. Security and Risk Control – The system tackles fraud, black‑market recharge, and refund abuse through a three‑stage risk model (pre‑detection, in‑process detection, post‑audit). Over 500 risk‑strategy models analyze device fingerprints, user location, transaction patterns, and blacklist malicious accounts. Real‑time interception, flexible verification, and account‑level bans protect against illicit activities.

4. Global Billing Capability – Since 2016, Mi Master supports 80+ payment channels in 180+ countries. A micro‑service architecture enables region‑specific deployment (Europe, North America, South America, Oceania) and centralized configuration synchronization via queues. Cross‑border network acceleration and tunnel‑based data transmission ensure low latency (<3 s for 97 % of requests) and reliable monitoring.

The platform offers a one‑stop billing solution: unified APIs hide channel differences, automatic channel selection via big‑data analysis, cloud‑native deployment, and extensive account services (over 10 billion personal accounts, loyalty, subscription). It also provides self‑service reconciliation, multi‑level revenue sharing, and marketing tools such as first‑charge bonuses, coupons, and discounts.

During the Q&A, participants asked about refund windows, anti‑fraud measures, supported payment methods (WeChat Pay, QQ Wallet, UnionPay, optional Alipay), and pricing models. The architect emphasized that the service itself is free; fees depend on industry and channel negotiations.