My Amex AU wants to make a large purchase using my account

[cottoncrown]

"Technically afford" doesn't sound good to me. Lending friends large sums of money is almost always a bad idea in my opinion.

[enharu]

For the most part, you should be fine.

Worst case scenario you will get FR and all you need to do is to send the tax docs back. Just a minor inconvenience, and the chances of it happening is somewhat slim.

[Marcos8]

If it was me I probably wouldn't be comfortable with an AU making a purchase like that. Why doesn't this person have their own card to put this on? Why did they have to be put on as an AU on your card? And if it's because of poor scores or little history when it comes to repaying debts, maybe thats an indicator they might not be a reliable person to "loan" money to... and it's not even your money you are loaning them... it's someone else's. That's just my personal opinion of course ymmv.