SONIA sterling overnight index average

Source: Bank of England Statistical Database, series IUDSOIA (SONIA). Licence: SONIA data licensed under the Open Government Licence v3.0 and copyright the Governor and Company of the Bank of England. The trade marks “Bank of England” and “SONIA” are registered trade marks of the Bank of England (terms). Files: data/raw/boe-sonia.csv.

Reading this series

SONIA is the sterling overnight index average, the risk-free reference rate for sterling and the benchmark that replaced LIBOR in that role. The Bank of England publishes it from transaction data, but it does not set it: it is a market rate reflecting unsecured overnight borrowing. This page uses Bank of England series IUDSOIA, under the Open Government Licence, with history from 1997 that includes the 2018 reform of the benchmark.

Because it is a market rate, SONIA moves daily and is not stepped. The headline is the latest daily print; the chart and the long-run statistics use month-ends, which keeps the drawn series readable. Read the value with its as-of date, then the "versus the previous reading" line for the most recent change. Mean, median, low and high summarise the observations in this build, not an official average. Chart and Table present one series two ways, range buttons filter the window, and Explore loads zoom and pan only when asked. SONIA is not Bank Rate, and it is not a mortgage or savings rate.

About this desk

The Switzerland desk leads with the SNB policy rate, from the BIS central bank policy rate series for Switzerland, then ECB, UK and US rates. The BIS series is the SNB policy rate from June 2019, the mid-point of the SNB's target range for the three-month Libor from 2000 to 2019, and the discount rate before that — stitched into one comparable series and drawn as daily steps. It is a policy rate, not a mortgage or deposit rate.

All desks show the same build-wide series in a different order, so switching desks changes the menu, not the figures. Values are republished with attribution to the BIS, and this page is not an official BIS publication. The build ingests no Swiss retail rate series, so none is shown. This is not financial advice, and readings may lag their source.