Posted: Sat Jan 21, 2023 3:45pm
You need to time your move carefully. The Spanish tax year is the calendar year. If you move to Spain permanently with more than six months of the year remaining, you are classed as tax resident for the WHOLE of that year, even though you may have spent the first few months living in the UK. All of your income and capital gains in that calendar year will then be subject to the attentions of the Spanish tax man, regardless of where they have arisen, in Spain or overseas. If you move here in the second half of the year, you won't become tax resident until the following calendar year.
Your best bet is to sell your UK house this year before you move to Spain, lodge with friends or relatives, or rent, then move to Spain in the second half of this year. Please note that, if moving here permanently, the day you first enter Spain is the day from which you are classed as ordinarily resident, not the day you get your residencia card or any other arbitrary date.