Sky surveys produce enormous quantities of data on extensive regions of the sky. The easiest way to access this information is through catalogues of standardised data products. XMM-Newton has been surveying the sky in the X-ray, ultra-violet and optical bands for 22 years. The XMM-Newton Survey Science Centre has been producing standardised data products and catalogues to facilitate access to the serendipitous X-ray sky. 4XMM-DR13 contains 983948 X-ray detections above the processing likelihood threshold of 6. These X-ray detections relate to 656997 unique X-ray sources.