If your MAGI is over $90,000 ($180,000 for married taxpayers filing joint), you can't claim the credit.
If over those limits it might be better to not claim them and let them get the education credit. Note that they would have to have a filing requirement and owe income tax to get any benefit since they would not receive the refundable portion of the credit. They must also on their return check the box saying that someone else can claim them.
