Am I able to claim any benefits in Spain due to my disability?

@John68M

This is definitely not my area of expertise, but I'll hazard an opinion. If the extra income is important to you, then it might be worth delaying a move to Spain, and/or checking with an appropriate professional in Spain about potential disability benefits.

I think most UK benefits will only be paid for periods of temporary absence abroad. If you permanently relocate to Spain, I'd imagine that you lose your PIP. But it also depends on age, as older folks are more protected. Here's a relevant page:

https://dls.org.uk/wp-content/uploads/2017/10/Taking-Your-Benefits-Abroad-Factsheet.pdf

On the other hand, I don't think Spain will pay any benefits to non-residents, or new residents who have not made any contributions to its social security system. You do have a straightforward path to residence (husband by employment, you by family reunification). And once you are legally resident, you can start making social security contributions (husband as employee, you as unemployed). The issue is how long it would then be before you qualify for some kind of Spanish disability benefit. I'd imagine it's between 2 years and 5 years (when you should be a permanent resident, a more protected status). A couple of relevant pages here:

https://ec.europa.eu/social/main.jsp?catId=1129&langId=en&intPageId=4799

https://ec.europa.eu/social/main.jsp?catId=1129&langId=en&intPageId=4793