Thanks for your quick response @Trevor S
So I know you can become VAT registered for a date up to 4 years prior. My understanding is if my brothers business became vat registered he would be able to reclaim the cost of the items.
Would that mean the £600 I paid to him. Does that then become a VAT supply of his commission that I can reclaim the cost on?
He would then report the commission in his sale turnover?