Hi Markj2704!Jennings
The tax treaty between the UK and Spain
Spain: tax treaties will give Spain the taxing rights on your employment income from the date you became resident.
You will need to complete a P85, confirming you have left the UK, but still remain employed by a UK employer
Get your Income Tax right if you're leaving the UK (P85).
The P85 should show your UK employment details, so that we can arrange for your employer to pay your employment tax free, as it is taxable in Spain. You will still be liable to pay class 1 National Insurance contributions.
Thank you