Catherine O'Reilly-Boyles

Hi - I'm an Irish/EU citizen planning on moving to Belgium but to keep my UK-based job, and my UK tax residency, which I have worked out is possible because of the amount of time spent physically working in the UK - although I will be spending around 60-70 days physically in the UK, I am able to meet the UK tax residency criteria via the 'sufficient ties' requirements (accommodation, work and 90-day) since i do not meet the automatic or overseas or UK residency tests. My issue is avoiding double taxation on this UK-taxed income, as I will be physically working at my UK job in Belgium, for the time that I'm not in the UK. I'm aware of the 183 day rule as part of the DTA which is that if I physically work in Belgium , even remotely for my UK job, I am still liable to be taxed on this income by the Belgian authorities. My question is a) is this 183 days of actual work, or is it 'employment' (i.e do weekends and annual leave count?) and b) if I am liable for tax by the Belgian authorities as well as the UK authorities, can I then claim back from the UK HMRC via self-assessment, or do I in fact claim back under the DTA from the Belgian authorities by showing I have already paid full tax from UK HMRC?