Apologies, fair enough, I should have provided more information.

He is based in Lima, Peru. For travel to Europe he usually travels KLM metal, given that it is the best connection for us. He is an American so he regularly travels to the US for business and family visits, and in that case tries to fly Delta.

His question is really about whether there are major differences transferring his Delta Skymiles account from US-based to Peru-based.