Vietnamese Engineers Build Telecom Billing System Serving 100 Million Subscribers

A Vietnamese billing system wins an award

Viettel High Tech (VHT) says its engineers built vOCS 4.0, a billing system for phone and internet service. The system won a prize in the "Enterprise Technology Deployment Excellence – Asia" category at the Telecom Review Excellence Awards 2026. It is the first time a Vietnamese company has won this award.

Key numbers

• Handles more than 300,000 transactions per second, or over 1 billion per hour.
• Can serve 100 million phone subscribers.
• Response delay is under 5 milliseconds.
• Claimed to cut hardware investment costs by 50% and deployment time by about 30%.
• Two data centers about 2,000 km apart. If one fails, the other takes over in under 2 minutes.

What a billing system does

A billing system is a key part of a phone network. It charges for every call, text, data use, service plan, and promotion as soon as it happens. This area is hard to build, and only a few large global tech companies have usually supplied these systems. Viettel began building its own in 2012. Its earlier version, vOCS 3.0, replaced a foreign system in 2017 for 90 million subscribers in Vietnam.

Why it matters

This shows Vietnam can build core telecom software that was once bought from abroad. VHT says the system can work on 2G to 5G networks and fixed-line service on one platform. A new plan that used to take days can now go live in hours. VHT also says it moved its Vietnamese subscribers and about 5,000 plans to the new system without stopping service, and it has launched the system in 10 overseas markets. It is ready to sell to other carriers.

What to watch

• Whether other international carriers buy vOCS 4.0.
• How well the system performs as it grows to 100 million users.
• How quickly 5G and digital services can bring new revenue through the system.