Domicile is a nebulis
concept when applied to taxation.
Everyone has a domicile of origin when applied to citizenship, and can be applied for taxation depending on many circumstances. The rules are different for landed immigrants who are not yet citizens, than those who are citizens, and can be different for domicile of origin citizens, and landed immigrants who have become citizens. The US remains one of the few places ( actually I can not think of any other ) who refer to landed immigrants as green card holders or resident aliens, and who also require that the aliens register every January.
The 183 day rules are usually for taxation purposes. My domicile of origin is Epsom, Surrey,
England. When I go to
England they do not seem to care if I have been
lost in wonderland for 4 weeks, four months or 40 years.
Michael