It's a massive step and needs a lot of research which you could do on expat forums, of which there are many, info sites such as UK in Spain, Anglo info, just Google and loads will come up .
Will you sell your UK home before moving here, or keep it as a Bolt hole if all goes pear shaped ?
Hopefully you will not need to work, as your chances of finding work are very, very low.
Your main priorities are :
Qualifying for residency you will need to prove income of at least 600 euros per month/ and or 6000 euros in the Spanish bank, and health cover. That's each adult.
Health cover -you will need private health cover for a year before being able to pay into the Spanish healthcare system,
Which is 60 euros per month each
If you are self employed, as you are with your online business, you will have to pay autonomo, 250 euros per month, although I think there is a new scheme whereby new self employed pay 50 per month for a year, then it increases.
Finance -make sure you have at least a year's money
Tax -even though your business is online, you will pay taxes in Spain on your income, and from any money you receive from the UK, including savings interest.
Taxes are different from the UK.Research inheritance tax, especially as you are moving to Murcia.
Schools -your children are at a very difficult age to start school in Spain. They will be severely disrupted in their education.They would probably be best in an international private school, which will be very expensive.
Even a state school has expenses eg school books, lunches , transport etc, possibly 600 plus euros to set them up
No children's allowance, or benefits in Spain is something to consider as well
In other words research, research and more research!
Don't expect Spain to be a cheap place to live- electricity is horrendous , and though some things are cheaper than UK, overall there's not a lot of difference.
Don't be annoyed if you get a lot of negative feedback, people are telling you how it is.
It's better to know now what you are up against, so you can weigh up the pros and cons.
This message was last edited by camposol on 30/09/2014.