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 Australia desk leads with the RBA's cash rate target, then New Zealand's OCR and the US federal funds rate, with the rest of the build's series after them. The cash rate is the RBA board's policy target for the overnight money market, published in the F1 daily and F1.1 monthly tables; the page uses the daily target for the headline and the monthly history for the long chart. Because it changes only at board meetings, the series is drawn as steps.

All desks show the same official series, reordered toward one economy; the figures do not change with the desk. Values are republished from official files without alteration. The build publishes no Australian mortgage or deposit rate, because no official series for those is ingested — the desk omits them rather than estimating. This is not financial advice, and readings may lag their source.