Financial centres that cater predominantly to non-residents – which we refer to as cross-border financial centres (XFCs) –are important intermediaries of cross-border financial flows. For analysing capital flows and international interconnectedness, it can be useful to distinguish countries that are home to XFCs from other countries. We improve on previous methodologies for identifying such centres by constructing a measure focussed on the intermediation activity inherent to XFCs and explicitly taking into account the non-normal distribution of this measure across countries when detecting outliers. We also minimise volatility in the set of countries identified as XFCs over time by de-trending the data and pooling years. Our methodology identifies a core set of 12 countries as XFCs over the 1995-2020 period, but the countries vary with time and different measures of activity.