Spirometry is a component of the diagnosis and management of respiratory conditions in primary care and should ideally be performed via referral to a primary care network respiratory diagnostic service or community diagnostics centre (CDC) with expertise in the diagnosis of the most common respiratory conditions and of less common diagnoses. Where limited resources create a challenge for testing everyone with a new suspected diagnosis of asthma, those with an intermediate probability should be prioritised for spirometry and also FENO where available. Spirometry confirmation of COPD is mandatory before any definitive communication with a patient that they have this diagnosis. Spirometry should be delivered and technically reported by registered healthcare professionals with an appropriate level of expertise and experience.