SPAIN/ UK PENSIONS / autonomo

Hi can anyone help on this subject as it must affect 1000s of Brits moving back to the UK

I have paid into the Spanish system here as a self employed person for around eight years 240/270 Euros a month I have now decided to move back to the UK,

My Q how do I obtain details of these payments to give to the UK social security / pensions dept
Or do I qualify for a payout from Spain on my retirement.

I really think this is an important topic as there must have been millions paid into the Spanish system.

regards