Background: COVID19 causes a wide spectrum of disease. However, the incidence and severity of sequelae after the acute infection is uncertain. Data measuring the longer-term impact of COVID19 on symptoms, radiology and pulmonary function are urgently needed to inform patients and plan follow up services. Methods: Consecutive patients hospitalised with COVID19 were prospectively recruited to an observational cohort with outcomes recorded at 28 days. All were invited to a systematic follow up at 12 weeks, including chest radiograph, spirometry, exercise test, blood tests, and health-related quality of life (HRQoL) questionnaires. Findings: Between 30th March and 3rd June 2020, 163 patients with COVID19 were recruited. Median hospital length of stay was 5 days (IQR 2 to 8) and 30 patients required ITU or NIV, 19 patients died. At 12 weeks post admission, 134 were available for follow up and 110 attended. Most (74%) had persistent symptoms (notably breathlessness and excessive fatigue) with reduced HRQoL. Only patients with disease sufficiently severe to warrant oxygen therapy in hospital had abnormal radiology, clinical examination or spirometry at follow up. Thirteen (12%) patients had an abnormal chest X-ray with improvement in all but 2 from admission. Eleven (10%) had restrictive spirometry. Blood test abnormalities had returned to baseline in the majority (104/110). Interpretation: Patients with COVID19 remain highly symptomatic at 12 weeks, however, clinical abnormalities requiring action are infrequent, especially in those without a supplementary oxygen requirement during their acute illness. This has significant implications for physicians assessing patients with persistent symptoms, suggesting that a more holistic approach focussing on rehabilitation and general wellbeing is paramount.