Primary care must ensure high quality lifelong care is offered to trans and gender minority patients who are known to have poor health and adverse healthcare experiences. This quality improvement project aimed to interrogate and audit the data of trans and gender minority patients in one primary care population in England. A new data collection instrument was created examining pathways of care, assessments and interventions undertaken, monitoring, and complications. General practitioners identified a sample from the patient population and then performed an audit to examine against an established standard of care. No appropriate primary care audit standard was found. There was inconsistency between multiple UK gender identity clinics’ (GIC) individual recommended schedules of care and between specialty guidelines. Using an international, secondary care, evidence-informed guideline, it appeared that up to two-thirds of patients did not receive all recommended monitoring standards, largely due to inconsistencies between GIC and international guidance. It is imperative that an evidence-based primary care guideline is devised alongside measurable standards. Given the findings of long waits, high rates of medical complexity, and some undesired treatment outcomes (including a fifth of patients stopping hormones of whom more than half cited regret or detransition experiences), this small but population-based quality improvement approach should be replicated and expanded upon at scale.