The coding of Long Term Conditions (LTCs) in primary care electronic records is central to a robust registration, recall and review system. In addition, failure to flag important diagnoses can lead to a coding inequality gap and potential harm due to a) failure to recall and optimise individuals b) failure to communicate patients’ diagnoses in correspondence c) prescription of medicines that may cause potential harm. It is known that there is a coding deficit in a number of LTCs including hypertension and atrial fibrillation.(1)It was hypothesised that there was a significant under-coding in heart failure (HF) across GP systems. This programme aimed to review healthcare records with a view to understanding the quantum of the coding deficit and ultimately make recommendations to avoid coding deficits in the future.A programme of work, named “Excellence in Heart Failure”, was initiated with an Academic Health Science Network (AHSN, now called Health Innovation Network), and one of the southern counties in England. The project was underpinned by several strands including a desktop review and clinical coding in hitherto un-coded patients with HF, and face to face optimisation of select patients with guideline directed therapies. Patients with potential HF were identified from electronic record searches on specific drug therapies and/or echocardiogram reports.The project ran for a year (2020/21).152 patients were added to the HF register (increasing the HF prevalence by 15%). 319 patients had specific code adjustments with the addition of a HFrEF (LVSD at the time of the project) code leading to more accurate care records. 151 patients received medication optimisation changes.A significant number of individuals with HF did not have a problem code in their primary care electronic record. This may have potentially lead to patients being lost to follow-up or sub-optimally treated.Desktop reviews can identify individuals with HF who are otherwise uncoded and potentially undertreated.  Under-coding can lead to an inequality gap and risk patients being lost to follow-up. It is essential that disease registers are maintained to deliver robust recall and review systems, and to reduce risk to patients.