If someone is trying to sell us something and we don’t want to buy it, we can explain we’re not interested. It’s another way of saying ‘I don’t want it’ in English. It’s just a little more polite and businesslike. You can see how we use the phrase in two different English conversations here.
This is our first new product. What do you think?
No, sorry. Not interested.
OK, we also have this. No, not interested.
How about this?
No, he’s definitely not interested. Do you have any balls?
I’ll offer you two a business proposition.
We’re not interested.
Well, you’ll be interested. Now, you’re a smart young man.
Don’t listen to him, Bruce.