SONIA

Japanese

SONIA

Also known as

Sterling Overnight Index Average

Last reviewed

September 25, 2026

This is a draft, shown for review before publication.

SONIA (Sterling Overnight Index Average) is a sterling benchmark rate that the Bank of England calculates and publishes every business day from the rates on unsecured overnight sterling deposit transactions. It is a trimmed mean that removes the top and bottom 25% of transactions by volume, published on the business day after the transactions.