Having been one of the desperate ex pats searching for employment in the Granada area of Spain I have found an answer that suits me and hope the idea will help others.
I now work for a live in care company in England that enables me to remain living in Spain. I work 3 weeks on 3 off or 5 weeks on 1 month of or any variation I need. As I am employed in the clients home with all food provided I have no costs while working.
I hope the idea brings the relief to others that I experienced.

As Concierge for the Spanish section of BE I would like to say hello and welcome.

BE is a very large expat website, so if you have problems finding your way around we have concierges who will try to direct you. The moderators for the Spanish forums are Mitzyboy and Fred James, moderators are there to ensure that the site runs smoothly within the rules of BE. Problems and complaints should always be addressed to a moderador who will look into the matter and deal with it efficiently and fairly. Our members who post in the Spain Forums are friendly and helpful with a wealth of knowledge of the issues of living in Spain. At the top of the page you will find a quirkily named thread called Free Beer which is full of important and useful information. Hope you enjoy your time participating in the forums.

Please let me know if you need any further help.

Rosemary

I know quite a few people who do that

I have often wondered how it works with tax & NI if you're here more than there

Congratulations and how kind to share your enterprising idea.
Just a note of caution. I imagine you are paying NI in the UK, which will also give you health cover in Spain.
Be very careful not to give DWP or HMRC the impression that you are undertaking ANY work in Spain for your employers. This includes answering emails, letters or phone call (even if they are simply acknowledging work offers etc). Be very clear in all communications with them that you undertake NO work at all abroad.

How does it really work?

Surely, as a resident of Spain, tax and NI must be paid in Spain?

You pay your tax and NI in england. I work for a company where I am directly employed on the PAYE system so I do not have to worry about doing my own tax ect.

but as a resident of Spain you have to make a tax declaration - I know you don't have to pay twice, so do you end up with a rebate or have to pay a bit extra?

also - with NI paid in the UK, how does that work with healthcare cover over here?

do you use the S1 reciprocal agreement?

I have declared the tax paid in England and so far have not had to pay anything in Spain over that.
I use the S1 reciprocal agreement.
If you wish to do neither of the above you can reclaim your tax ect from the british system and then declare your income on the spanish system to pay your tax ect there.

thanks for clearing that up

I think that this is a common misconception - AFAIK (Fred may come on to put us all straight), if you live in Spain, then worldwide income (other than pensions) MUST be taxed in Spain. You don't get a choice unless you wish to break the law!

If tax and NI are deducted at source in UK, then when you submit a Spanish tax form, you declare UK tax already paid and either get a rebate or pay any extra that may occur.

I just realised that I misread what Norma Brewis wrote

I thought she meant she declared in Spain, too - but I see now she didn't actually say that

Norma,
I was in an identical position. Just be very careful indeed what you say to HMRC when you renew your S1. If you give the slightest hint you answer an email phone call or letter to do with work in Spain, they may cancel your S1.
They did cancel mine. It was a nightmare to sort out, and cost me 18 months private health cover.

Yes you are right. There is a box on the tax declaration where you enter any tax paid in the UK and a box where you enter the income.

Tax is always deducted in the UK from income derived in the UK even if you are not UK tax resident. You can usually get the UK personal allowances against it which reduces the UK tax but you have to declare it in Spain. It is quite possible that you can end up paying more tax this way as Spanish allowances are lower and the tax rates higher but it isn't an option.

I also know 3 ladies who are currently working for similar care agencies in the UK, having previously been in difficult financial circumstances in Spain, and it is proving a lifeline for them. There doesn't appear to be any shortage of work, one person I know has been working almost continuously since last autumn with only 2 brief visits back to Spain (her husband is still based here, looking after things at this end). If you are single or don't mind living apart much of the time (needs must, I know, I'm sure I would consider doing the same if I needed to, although I pity the poor person who had me looking after them, I bet I wouldn't be asked to go back a second time!) it does seem a good option.

I have a similar job. I'm an Operating Department Practitioner and work for an agency which supplies healthcare workers to the public and private sector.

Although in my case my main residence is the UK because I spend a total of more than 7 months there a year and never spend more than 2 months at a time in Spain. As such, I do not qualify for free health care in Spain and have to have private health insurance cover for visiting here.

My job is not transferable to Spain, so I have little choice. I have to work in the UK. But having read this thread, I am wondering if I too would qualify for an SI under the reciprocal arrangement if I spent more time in Spain. My husband lives here and is registered for health care, so it wouldn't be that difficult, would it?