A CARTAC National Accounts technical assistance mission to St Kitts and Nevis, re-referenced the volume estimates of quarterly GDP for the years 2012–2022 using 2018 as the base and reference year from the previous 2006 base year. The series were developed for both Saint Kitts and for Nevis and a combined series for the Federal aggregate. The re-referencing exercise provided an opportunity to introduce some other improvements. Notably, the calculation of Final Intermediation Services Indirectly Measured (FISIM) consumed by each economic sector businesses and its allocation to economic activities. The updated series were also prepared using the International Standard Industrial Classification of Economic Activity (ISIC) revision 4 . These improvements align the updated GDP series with the standards set out in the 2008 System of National Accounts. In addition, the current price estimates of GDP by expenditure were also reviewed.