NPL operates the national time scale UTC(NPL) and maintains the UK’s primary frequency standards. These are used to contribute to global timekeeping and to distribute precise time and frequency information to users across the UK through services such as the MSF radio time signal, network time, and NPLTime®.
The National Timing Centre (NTC) is a major programme led by NPL, that is responsible for developing the UK’s first nationally distributed time infrastructure. The NTC programme strengthens the resilience of the UK’s timing and frequency services, enabling innovation in technologies such as 5G and 6G communications, smart cities, satellite links, and autonomous vehicles.
In 2026, NPL upgraded its Network Time Protocol (NTP) service with the addition of three diverse server locations and hardware timestamping to enhance the resilience, reliability and accuracy of network time.
How does a computer know the time and date, or when clocks are due to go forward or back? Every computer timestamps key events such as sending an email or saving a file using its internal clock. Most computer clocks rely on inexpensive quartz oscillators that can drift by several seconds per day and accumulate errors of many minutes over time. To maintain accuracy, the computer’s internal clock must regularly synchronise with a highly accurate and trusted external source of time.
NPL's Network Time Protocol service enables a computer to set its internal clock accurately by connecting to an NTP server, operated by NPL. The NTP transmits precise time codes over the internet, ensuring the time shown on a user’s computer is continuously synchronised to the UK’s national time scale – UTC(NPL).
NPL operates five independent NTP servers from diverse locations. These servers are synchronised to atomic clocks at NPL, which provide the national time scale - UTC(NPL). They are classified as stratum 1 servers, meaning they are directly linked to primary reference sources, offering a robust ground-based alternative to satellite signals.
Multiple additional NTP servers in different locations are available to enhance resilience, so your connection stays as reliable as possible no matter where you are. The servers are monitored 24 hours per day and use both software and hardware timestamping to deliver increased timekeeping accuracy – ensuring a fast and accurate service.
Led by NPL, the NTC programme is developing the UK’s first nationally distributed time infrastructure that will improve security and resilience, communication, and implementation of new technologies, and pave the way for trusted time and frequency across the country.
Our NPLTime® Services offers industry access to terrestrial timing signals, traceable to
UTC(NPL), with service level agreements.