This visa - known in Spanish as the 'No Lucrativa' visa - meaning it is not valid if you wish to be able to work in Spain, can nevertheless be a very interesting option for non-EU – including British citizens (post-Brexit) – who wish to reside in Spain.
If you are earning more than €2,260 Euros on a monthly basis (whether based on a pension or any other kind of regular income) you can apply for residency in Spain – though please note, for non-working purposes only.
If more than one person is applying (for instance you intend to come with your spouse/partner and children) the income required will increase by approximately €565 per month for each additional member.
You can also apply even if you do not have regular income, but simply have deposit/s in bank account/s over that amount during the time of residency, so over €27,115 for 1 member and an additional €6,780 (approx.) for each additional member.
The visa duration is for one year initially, renewable on a 2 yearly basis, until such time as you have spent 5 years resident in Spain, when you can request a long-term visa.