K-band (3σ) selected source counts (per square arcsecond per 0.5 magnitude) in ELAIS-N1 (red crosses) and Lockman Hole (red triangles) from the χ² catalogue. In Boötes, we show source counts from the merged catalogue (blue circles). We also show the galaxy counts from the COSMOS deep area taken from Laigle et al. (2016) for comparison (black squares). Additionally, the galaxycounts from the UKIDSS-DXS DR10 catalogues (Lawrence et al. 2007) in both ELAIS-N1 (black crosses) and Lockman Hole (black triangles) are shown. In all cases, we have attempted to remove the contribution from foreground stars via a cross-match to Gaia DR2 catalogues in each field. Vertical lines show the 3- and 5-σ magnitude depths in ELAIS-N1 (dashed lines) estimated from random, source free 3′′ diameter apertures. Poissonian error bars are shown only where they are larger than the symbol size, but there may be other cosmic-variance related errors.