The AnTIC trial is a 40-site, pragmatic, patient randomised superiority trial comparing an experimental strategy of once daily antibiotic prophylaxis against a control strategy of no prophylaxis. Both groups will otherwise receive usual care including on demand discrete treatment courses of antibiotic treatment for UTI. The trial will be set in both primary and secondary National Health Service (NHS) care. Participants and their clinicians will not be blinded to the allocated intervention but central trial staff managing and analysing trial data will, as far as possible, be unaware of participant allocation. The investigators will also assess participant perception of benefit firstly by completion of a treatment satisfaction questionnaire on exit and secondly by qualitative analysis of semi-structured interviews on trial completion exploring the views and attitudes of a purposive sample of participants towards the trial intervention. The primary economic analysis will assess the cost per UTI avoided but we will also perform a cost-utility analysis and a contingent valuation study. Bacterial ecological change will be assessed by comparing changes in resistance patterns of E. coli in urine and perianal swabs. The investigators have formulated a recruitment plan to progressively build to a target of 372 participants over 24 months.