Introduction to the STS System
I. What Is the STS System?
STS, short for Standard Transfer Specification, is an internationally adopted secure messaging standard designed for prepaid metering. It was originally drafted by ESKOM, the national power utility of South Africa, and is now maintained and certified by the STS Association.
The STS protocol ensures secure transmission of prepaid tokens between vending systems and metering devices. It protects the interests of utilities while enabling interoperability, security, and transparent operation of prepaid systems for electricity, water, and gas.
II. Development History of STS
The STS system has evolved significantly since its introduction:
1993 — Birth of the STS Concept
ESKOM introduced the earliest “transmission-based STS” for prepaid metering.
1997 — Establishment of the STS Association
Five South African companies, including SHEM and COMS, jointly founded the STS Association to promote and regulate the STS standard.
2007 — International Standardization
The IEC/TC13 Committee officially incorporated South Africa’s STS into the international standard IEC 62055 series, marking global recognition.
2019 — Release of STS 2.0
To improve compatibility and support the 2024 TID rollover, the STS Association released STS 2.0, enhancing encryption, token processing, and protocol implementation.
Zhongyi Smart is an officially certified member of the STS Association, authorized to manufacture and certify STS-compliant products.III. Global Adoption of the STS Protocol
III. Global Adoption of the STS Protocol
The STS protocol is widely used across multiple continents:
Africa
- Commonly adopted in countries such as:
- South Africa
- Tanzania
- Ghana
- Uganda
- Senegal
…and many others.
Asia
Widely required in:
- India
- Bangladesh
- Indonesia
Europe
- Countries using STS include:
- Moldova
- Latvia
- Estonia
- Lithuania
- Belgium
- Poland
Oceania
- New Zealand
South America
- Argentina
- Colombia
North America
- United States
IV. Transition to STS 2.0 and Market Standardization
With the 2024 TID (Token Identifier) rollover, the global prepaid metering market is undergoing a major transition:
Legacy STS 1.0 tokens will expire after the TID flip
STS 2.0 introduces updated encryption and extended token lifetime
The new HSM (Hardware Security Module) strengthens token generation security
Non-standard prepaid solutions in several markets will be unified under STS 2.0
Countries with customized legacy token formats—such as Senegal (dual-wallet tokens), Bangladesh (special recharge tokens), Uganda (relay tokens), Colombia, and Ghana—will transition to standardized STS 2.0 for full interoperability.
This shift will create a more unified, secure, and compatible global prepaid metering environment.
V. About Zhongyi Smart
Wuxi Zhongyi Smart Technology Co., Ltd. specializes in the R&D and manufacturing of smart water meters, electricity meters, and gas meters, serving more than 90 countries worldwide.
Our STS-compliant prepaid products support modern utilities in building secure, efficient, and scalable metering systems.
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