Hi, I've sold my apple to a person and I forgot to take my Apple ID off will they be able to purchase anything on the Apple TV

Not unless they have your Apple ID password.

If you set up your Apple TV to make purchases without re-entering your password then YES, they can purchase/rent movies. You are asked this question the first time you try to buy something. Do you remember what you did?

albert42440 wrote:

Hi, I've sold my apple to a person and I forgot to take my Apple ID off will they be able to purchase anything on the Apple TV

It is possible. You should change your AppleID password and go into you account under iTunes and deactivate that device on your account. If you want an extra layer of protection you could remove the credit card on your account for a while. You would not be able to make any purchase either until you re-add it, but you also know they can't.

There are other issues beside buying content. They might be able to access your content. So if you use iCloud your photos might be showing up, music, podcasts, TV Shows, etc.