Bank account holders have reported difficulties accessing the Halifax app and online banking services since around 8:30 AM, with users voicing concerns on Downdetector. In the UK, including cities like Birmingham, London, and Bristol, 69% of users experienced problems with the app, 12% faced login issues, and 13% reported mobile banking problems. A notice on the app indicated a technical error preventing users from logging in. Downdetector tracks disruptions in online services by allowing users to report issues, providing real-time analysis of reported problems.