UK Certificate of Tax Residency - Double Taxation Agreements

Hi there, I'm trying to understand if my partner and I are tax residents of the UK. We live in Portugal and have residency here however we signed upto the NHR, double taxation treaty when we moved over, pay all our taxes to HMRC and have a UK based Ltd company which we run remotely - all of our income at this point has been generated in the UK. We now have the opportunity to sell on a Spanish marketplace but they require a tax residency certificate; on reading the HMRC guidance it appears that we can apply as our country of residence has a double taxation agreement - am I reading this correctly?

Hi RuthHW,
HMRC cannot advise you on this as your residence status is for you to determine based on guidance available.
Please refer to:
RDR3 Statutory Residence Test
Thank you.