Trevor Eve's son? Just come to this series late, absolutely engrossing! Not understanding what Sir Philip's son is after, his name on a letterhead, for what? Is it part of the plot or just to show what a bastard he is?
The father is a prominent businessman with a British title. The son wanted to use his father's name and business letter head on a business proposal he was working on....presumably to make it seem like the deal was backed by his father's company. He said they would be impressed with his father's British title.... and it would be all he needed to push the deal through.
Later his father turned him down after looking into the people the son was doing business with and found they were involved with criminal enterprises and didn't want to be involved.