In the English National Health Service, most patients can use an online platform to send a written request to the practice, in addition to calling or visiting the practice in person. However, there are concerns that the availability of an online access route to primary care can adversely impact healthcare provision for older or lower socioeconomic groups. To examine those concerns, we explore the differential timing of online platforms' implementation between 2019 and 2020 across 289 practices covering over 2.5 million patients in North West London. We find no evidence of an impact of the online access route on age and socioeconomic-related inequity in synchronous interactions in primary care, but observe an increase in all interactions in this setting and in some cases, a small reduction (worst case, no changes) in unplanned hospital care. These findings suggest that having an online access route to primary care can improve the provision of healthcare services, at no detriment to patients from older and lower socioeconomic groups.