INTRODUCTION The COVID-19 pandemic is ongoing yet, due to the lack of a COVID-19 specific tool, clinicians must use pre-existing illness severity scores for initial prognostication. However, the validity of such scores in COVID-19 is unknown. METHODS The North West Collaborative Organization for Respiratory Research (NW-CORR) performed a multi-centre prospective evaluation of adult patients admitted to hospital with confirmed COVID-19 during a two-week period in April 2020. Clinical variables measured as part of usual care at presentation to hospital were recorded, including the CURB-65, NEWS2, and qSOFA scores. The primary outcome of interest was 30-day mortality. RESULTS Data were collected for 830 people with COVID-19 admitted across 7 hospitals. By 30 days, a total of 300 (36.1%) had died and 142 (17.1%) had been in ICU. All scores underestimated mortality compared to their original validation in non-COVID-19 populations, and overall prognostic performance was generally poor. Among the 9low risk9 categories (CURB-65<2, NEWS2<5, qSOFA<2) 30-day mortality was 16.7%, 32.9% and 21.4%, respectively. Multivariable logistic regression identified features of respiratory compromise rather than circulatory collapse as most relevant prognostic variables. CONCLUSION All existing prognostic scores evaluated here underestimated adverse outcomes and performed sub-optimally in the COVID-19 setting. New prognostic tools including a focus on features of respiratory compromise rather than circulatory collapse are needed. We provide a baseline set of variables which are relevant to COVID-19 outcomes and may be used as a basis for developing a bespoke COVID-19 prognostication tool.