Immigration

Were you permanent or temporary residents in 2017?

I didn't think you could retain your residency after leaving for over 5 years but it looks like I'm wrong.

https://balcellsgroup.com/how-long-outside-spain-without-losing-residency

https://www.immigrationspain.es/en/maximum-time-outside-spain-without-losing-residency/

How long did you have the geen card? If under 5 years then it would expire when outside Spain for more than 6 months. If over 5 years then you would be a permanent residence and it only expires if you are outside Spain for more than 6 consecutive years.

Did you cancel your padron , green card and inform the tax office you were leaving? Do you still have property in Spain? If not They could query why you have not submitted a tax return in those years..

The only thing to do is try it and see. Apply for an appointment for a TIE and see if it's accepted. 

Morning

This may be of some use to you in the future.

https://www.healthplanspain.com/blog/spain-news/1858-spanish-government-abolishes-six-month-absence-restriction-temporary-residency.html

Paul

Essentially you're talking about applying for a TIE under the terms of the Withdrawal Agreement but 2.5 years on I'm not sure that that route is still open is it?

Even if it is you would need to demonstrate that you had been living in Spain legally prior to Dec 31st. 2020 and for that you would have had to  demonstrate that you had qualifying health care in place on or before that date. Without it an application will fail and it's proved a fatal blow to many an otherwise genuine and timely application.

You say you have a SIP card but of itself it is worthless if your entitlement to it has expired as it almost surely must have if you've been out of the country for some 5 years. On what basis did you obtain it?

There is another option and that is to simply return to Spain on your green residencia and carry on as if you'd never left, it's not one I would recommend though!

A further factor you may not have considered is that of a driving licence exchange agreement for which was finally achieved earlier this year. Under it's terms you had 6 months from March 16th to effect an exchange after which it would no longer be possible and a Spanish test taken, that deadline is now just some 10 weeks or so away.

There is a caveat!

If you happen to have renewed a UK licence in the period between Jan 1st 2021 and now then that licence will not be eligible for exchange at all the problem being that technically renewing a driving licence must done  in the country in which you are legally resident so it follows that if you did it in UK you cannot claim to have been Spanish resident at the same time.

As suggested 'suck it and see' may be your only practical way forward.

I wish you good luck!