Mozz: To be considered a donation from you, you would have had to "own" it. Then, depending on UK tax purposes, you may get charged with the "increase in value" or basically, your "profit" on the card as income to you. Yes, it can be a "gift" back to Jeremy, but, as he is just 17-18 yrs. old, unless he is gainfully employed already, then I don't think he would owe anything. ***
Keith
***Not a tax attorney, please consult a CPA or Tax att'y for official answers. You can prolly even call the IRS yourself and get the answer to this unique inquiry.